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Autonomic changes and stress response in psychopathology
224
Poster presentations sessions 1,2,3 / International Journal of Psychophysiology 69 (2008) 207–241
Electrocortical correlates of mental rotation in high vs. low intelligent individuals V. Varriale a, M.W. Van Der Molen b, V. De Pascalis a University of Rome qLa Sapienzaq, Department of Psychology, Rome, Italy b University of Amsterdam, Department of Psychology, Amsterdam, The Netherlands
a
Low and high (Raven) intelligent individuals performed on a mental rotation task requiring them to decide whether a letter is normal or backwards (mirror reversed). The typical finding is that this decision takes longer as the letter is rotated away from the upright. This study examined the question of whether high-intelligent individuals are better in mental rotation than lowintelligent individuals and whether the anticipated individual differences would be manifested in brain-potential and EEG frequency band measures recorded at the scalp during task performance. The performance results showed that high-intelligent individuals were faster and more accurate than low-intelligent individuals and this difference did not change across rotation angle. A similar pattern was observed for P3 amplitude recorded over the parietal and centro-parietal scalp regions. EEG frequency band amplitudes were calculated during a 1 s window preceding stimulus onset and two subsequent 1 s windows following stimulus onset. High-intelligent individuals had higher alpha-band amplitudes in all three windows compared to low-intelligent individuals. This difference increased with rotation angle for the baseline (preparation) window. Finally, theta band amplitude discriminated between high- vs. low individuals but performance level determined the direction of this difference (i.e., negative for good performers and positive for bad performers). The current findings point to an interesting dissociation between performance and frequency band measures associated with fluid intelligence. The former seem to reflect individual differences in global processing speed while the latter point to individual differences at a central processing level manipulated by the mental rotation task.
doi:10.1016/j.ijpsycho.2008.05.066
Sympathetic arousal and arousability predicts subsequent sleep quality C. Lombardo, C. Baglioni, A. Devoto, F. Lucidi, C. Violani University of Rome “La Sapienza”, Department of Psychology, Rome, Italy The aim of this study was to evaluate whether individuals with primary insomnia, in comparison to normal sleepers, show consistently higher autonomic arousal levels or changes in autonomic arousal which is systematically associated to differences in the quality of their night-time-sleeping. To address this aim, skin conductance levels (SCL) and inter beat intervals (IBI) were monitored before and after five consecutive nights in two different experimental conditions: 3 min with the instruction to rest and 3 min while providing acoustic stimuli inducing an orienting reflex. Twenty-three participants were recruited for the study, twelve people with insomnia and eleven good sleepers. The selection of the participants consisted in a first screening phase followed by a clinical interview and two weeks of assessment through the use of sleep diaries. Groups were matched for gender and age. Physiological indices were recorded in the participants' own homes through portable devices for one week (weekends excluded), during which sleep–wake cycles were monitored through actigraphic recording and sleep diaries. Sleep Efficiency Index (SEI), obtained as the ratio between total time spent sleeping divided by the total time spent in bed after lights off, was computed for each night. The SEIs were ordered from the worst to the best. Due to technical problems, two participants only had recording for 4 nights. Consequently, one night was excluded for the whole sample. Results showed that the SEI was always higher in good sleepers as opposed to people with insomnia which, moreover, presented higher within subjects and within group variability than did the control group. Regarding the physiological measures, it was found that sympathetic arousal measured by SCLs predicted the quality of the sleep during the subsequent night. Specifically, both groups showed marginally high rest arousal and significantly high arousal in response to stimulation (arousability) linked to low SEI during the subsequent night. The existence of a relationship between sympathetic arousal and sleep quality is consistent with previous results (e.g. Broman, Hetta, 1994). With respect to IBIs results evidenced no systematic
change across both groups and nights of different qualities. In summary, results demonstrated that the variability of sleep quality, which is a central feature of insomnia, is also related to varying levels of evening autonomic arousal and arousability. The same relationship was found also in good sleepers.
Reference Broman, J.E., Hetta, J., 1994. Electrodermal activity in patients with persistent insomnia. J. Sleep Res. 3, 165–170.
doi:10.1016/j.ijpsycho.2008.05.067
A method to map the cortical representation of hand muscle by transcranial magnetic stimulation based on spline interpolation F. Sartucci a, D. Borghetti b, T. Bocci b, E. Petacchi c, A. Guzzetta c, G. Cioni c, L. Murri b a Department of Neuroscience, Pisa University Medical School and Institute of Neuroscience, CNR, Pisa, Italy b Department of Neuroscience, Pisa University Medical School, Pisa, Italy c Department of Developmental Neuroscience, Stella Maris IRCCS, Pisa, Italy Background and objective: To study somatotopic organization of the motor cortex, transcranial magnetic stimulations (TMS) plays nowadays a fundamental role. Aim of our study was to develop and to validate a new method to map the cortical representation of two intrinsic hand muscles (abductor digiti minimi, ADM, and opponent pollicis, OP), using a two dimensional spline interpolation of Electromyographic (EMG) responses peak amplitudes by means of TMS. Methods: Ten healthy volunteers (mean age ± SD: 35.3 ± 4.7 years, 4 males and 6 females) were enrolled. For TMS, a figure-of-eight coil was placed tangentially to the scalp, over a predefined grid drawn on a cap worn by the subject and was subsequently moved from a grid node to another recording the motor evoked responses (MEP) from each node. EMG responses were recorded from right abductor digiti minimi (ADM) and opponent pollicis (OP) muscles. Averaged EMG peak amplitudes obtained at each node and their coordinates were then used to perform spline interpolation using Statistica 6.0® software (StatSoft Inc., USA) and to derive other parameters like Center of Gravity (CoG). Interpolated data were used to calculate fitted peak coordinates and subsequently compared with original parameters with a paired t-test. Results: Arithmetical mean of all resting motor threshold at the hotspot was 50.6 ± 3.4% of the maximal stimulator output; average amplitude was 1.72 ± 0.80 mV and its coordinates, expressed as median, were x = 4.5 cm and y = 0.0 cm. Mean CoG was located at x = 4.86 ± 0.57 cm and y = 0.35 ± 0.10. Mean interpolated peak coordinates for ADM were xf = 4.86 ± 0.58 cm and yf = 0.36 ± 0.12 (p level = not significant versus CoG), while mean fitted peak amplitudes was 0.87 ± 0.47 mV. Averaged amplitudes for each grid's point and their coordinates obtained from ADM and OP were interpolated and subsequently two dimensional mapping of the motor cortex was performed for each subject. Discussion: The present study suggests that is possible to precisely and accurately map the primary motor cortex using two-dimensional spline interpolation of peak to peak amplitudes following multiple TMS, complementary and not substitute to traditional conventional method, useful in the assessment of a wide variety of disorder, either congenital or acquired. Significance: Our methodological study, based on a spline interpolation, results in a smooth, easy to read, amplitude colour-scaled map and allows an easy intra- and inter-subject motor cortex mapping and comparison.
doi:10.1016/j.ijpsycho.2008.05.068
Autonomic changes and stress response in psychopathology C. Pruneti, F. Fontana, C. Fante University of Parma, Department of Psychology, Parma, Italy 89 subjects were consecutively examined into an outpatient clinical centre. The following diagnosis ware made according to the DSM IV - TR
Poster presentations sessions 1,2,3 / International Journal of Psychophysiology 69 (2008) 207–241
criteria1: generalized anxiety disorder (GAD, n = 35), major depression episode (MDE, n = 13), panic attack disorder (PAD, n = 14), obsessive compulsive disorder (OCD, n = 10) Anorexia Nervosa (restricted type) (9). Inclusion exclusion criteria: subjects with physical illness or comorbility with other I or II axis disorders of the DSM IV-TR were excluded. All the subjects underwent a continuous and simultaneous registration of fourth physiological parameters strictly connected with the autonomic arousal: skin conductance response (SCR), heart rate (HR), peripheral temperature (PT) electromyography of the frontal muscle (EMG). All the parameters were continuously registered in three consecutive phases: baseline (registration at rest), stress presentation and recovery. Each phase was 6 minute duration with a stop of 10 s between the phases and 3 min of adaptation before the start of the registration. At the time of the diagnosis all the subjects were free of any medication for at last of three months. Data of the fourth groups of subjects was compared in regard of each of the registered physiological parameters by using the means value of the last minute of the registration at rest, and two activation indexes: stress response” and “recovery after stress”. Furthermore, in each physiological parameters, and for each diagnostic group, mean values in the three different phases (last minute of the rest, first minute of the stress, last minute of the recovery) were compared to evacuate the fourth PPF parameters trend. Statistical tests were utilized to evacuate possible differences into the three phases, and the significance of the changes between one phase and the others. Results from the statistical analysis had shown that in GAD patients and PAD patients, SCR mean values are higher than MDE and OCD (p b .001), the amplitude of the galvanic response is also significantly different (p b .05). Furthermore, the HR response is also higher in GAD than in the other three groups (p b .02). So, OCD and MDE patients seem to be characterized by a flattened profile of all considered parameters. The results suggest an interesting hypothesis of a new tool for the differential diagnosis, represented not only by a single measure as the Skin Conductance as recommended in the DSM IV TR (for the Anxiety Disorder only), but of a specific and typical pattern of autonomic response for some psychopathological syndromes.
doi:10.1016/j.ijpsycho.2008.05.069
Imbalanced activation of the distributed neural system for face perception in social phobia C. Gentili a, M.I. Gobbini b, E. Ricciardi c, N. Vanello d, P. Pietrini c, J.V. Haxby e, M. Guazzelli a a Unit of Clinical Psychology, AUO Pisa, Department of Psychiatry, Neurobiology, Pharmacology, and Biotechnologies, University of Pisa, Pisa, Italy b Department of Psychology, University of Bologna, Bologna, Italy c Laboratory of Clinical Biochemistry and Molecular Biology, Department of Experimental d Department of Information Engineering, University of Pisa, Pisa, Italy e Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NE, US Social Phobia (SP) is a marked and persistent fear of social or performance situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. Human faces are perceived as socially threatening by social phobic patients (SPP). To study how and if face processing is altered in SPP in the distributed neural system for face perception, we designed an fMRI study in which we used an event-related design to present emotional faces (with angry, fearful, disgusted and happy expressions), neutral faces and scrambled pictures (visual baseline). Eight right-handed subjects (4M/4F) (mean age 39 ± 7) with a diagnosis of Social Phobia according to the DSM-IV-TR (APA 2000) criteria and seven right-handed healthy control subjects (4M/3F) (mean age 30 ± 7) were recruited. Consistent with previous reports, we found hyperactivation in SPP, as compared to healthy controls (HC), of regions involved in emotional experience, namely the left amygdala and insula. In addition, we found a stronger response in SPP in the superior temporal sulcus (STS) bilaterally, a part of the core system for face perception that is involved in the appraisal of expression and personal traits. We also found weaker activation of the left fusiform gyrus, left dorsolateral prefrontal cortex and bilateral intraparietal sulcus in SPP. Patients showed augmented processing of information about emotional expression and a stronger and probably wary
225
emotional response to faces. On the other hand activity is decreased in areas for attention and for processing other information from the face, perhaps as a result of this feeling of wariness. These results suggest an imbalance of activity of the distributed neural system for face perception in SPP.
doi:10.1016/j.ijpsycho.2008.05.070
Low-density EEG study of dynamic properties of cortical sleep slow oscillation in humans: Perspectives for clinical applications A. Gemignani a, D. Menicucci b, A. Piarulli a, A. Landi c, U. Olcese c, B. Ghelarducci a, P.D. Ascanio a a University of Pisa, Department of Human Physiology qG. Moruzziq, Pisa, Italy b IFC, CNR, Pisa, Italy c University of Pisa, Department of Electrical Systems and Automation, Pisa, Italy Aim: High-amplitude slow waves with long-range synchrony represent the hallmark of slow wave sleep (SWS) and anesthesia. Intracellular recordings in animals have revealed that during SWS the membrane potential of cortical neurons oscillates between a state of deep hyperpolarization and a state of wake-like depolarization. This cellular behavior, referred to as sleep slow oscillation (SSO), represents the fundamental cellular phenomenon underlying neural activity in SWS. SSO is also detectable in human EEGs and is characterized by typical frequencies less than 1 Hz. Aim of the study is to identify by 32 channels EEG dynamic and spatial features of cortical SSO. Methods: EEG recordings were performed in 8 healthy right-handed male subjects (age 20–25 yrs) during the first sleep cycle of the night. All EOG, ECG and respiratory artifacts were removed by ICA algorithm. Following the approach used by Massimini et al. (J Neurosci, 24:6862-70, 2004), who employed a HiRes EEG (256 channels), each channel was scanned with a sliding window in order to identify all signal shapes with the following features: (a) a negative zero crossing and a subsequent positive zero crossing separated by 0.3–1.0 s, (b) a negative peak between the two zero crossings with voltage less than − 80 μV, (c) a negative-to-positive peakto-peak amplitude N 140 μV. Results: Results indicate that each SSO originates more frequently in frontal scalp regions and propagates over the scalp in a fronto-occipital direction at an averaged speed of 5 m/s. Conclusion: The main findings of this work are 1) our data are consistent with those obtained by Massimini et al., (2004) by HiRes EEG; 2) the results obtained by 40 channels EEG open new possibilities to explore routes of research in different fields of applied neurophysiology and, particularly, of neurophysiopatology.
doi:10.1016/j.ijpsycho.2008.05.071
Perceptual learning of speech processed by a Cochlear Implant simulator — An fMRI investigation G. Rota a,c,f, L. Turicchia b, R. Veit c,d, M. Guazzelli a, N. Birbaumer c,e, G. Dogil f University of Pisa, Department of Psychiatry, Neurobiology, Pharmacology, and Biotechnologies, Pisa, Italy b Massachusetts Institute of Technology, Research Laboratory of Electronics, Cambridge, MA, USA c University of Tuebingen, Institute for Medical Psychology and Behavioural Neurobiology, Tuebingen, Germany d Max Planck Institute for Biological Cybernetics, Tuebingen, Germany e National Institutes of Health, NINDS, Human Cortical Physiology Section, Bethesda, MD, USA f University of Stuttgart, Institute for Natural Language Processing, Stuttgart, Germany
a
Cochlear Implants (CIs) are prosthetic devices that restore hearing in profoundly deaf people. CIs convert sound waves into electrical impulses stimulating the auditory nerve. Newly implanted CI users encounter major difficulties deciphering speech. As time passes, a perceptual learning process induces a modification of the cortical networks that permit speech decoding, resulting in an increased speech intelligibility.
Poster presentations sessions 1,2,3 / International Journal of Psychophysiology 69 (2008) 207–241
Electrocortical correlates of mental rotation in high vs. low intelligent individuals V. Varriale a, M.W. Van Der Molen b, V. De Pascalis a University of Rome qLa Sapienzaq, Department of Psychology, Rome, Italy b University of Amsterdam, Department of Psychology, Amsterdam, The Netherlands
a
Low and high (Raven) intelligent individuals performed on a mental rotation task requiring them to decide whether a letter is normal or backwards (mirror reversed). The typical finding is that this decision takes longer as the letter is rotated away from the upright. This study examined the question of whether high-intelligent individuals are better in mental rotation than lowintelligent individuals and whether the anticipated individual differences would be manifested in brain-potential and EEG frequency band measures recorded at the scalp during task performance. The performance results showed that high-intelligent individuals were faster and more accurate than low-intelligent individuals and this difference did not change across rotation angle. A similar pattern was observed for P3 amplitude recorded over the parietal and centro-parietal scalp regions. EEG frequency band amplitudes were calculated during a 1 s window preceding stimulus onset and two subsequent 1 s windows following stimulus onset. High-intelligent individuals had higher alpha-band amplitudes in all three windows compared to low-intelligent individuals. This difference increased with rotation angle for the baseline (preparation) window. Finally, theta band amplitude discriminated between high- vs. low individuals but performance level determined the direction of this difference (i.e., negative for good performers and positive for bad performers). The current findings point to an interesting dissociation between performance and frequency band measures associated with fluid intelligence. The former seem to reflect individual differences in global processing speed while the latter point to individual differences at a central processing level manipulated by the mental rotation task.
doi:10.1016/j.ijpsycho.2008.05.066
Sympathetic arousal and arousability predicts subsequent sleep quality C. Lombardo, C. Baglioni, A. Devoto, F. Lucidi, C. Violani University of Rome “La Sapienza”, Department of Psychology, Rome, Italy The aim of this study was to evaluate whether individuals with primary insomnia, in comparison to normal sleepers, show consistently higher autonomic arousal levels or changes in autonomic arousal which is systematically associated to differences in the quality of their night-time-sleeping. To address this aim, skin conductance levels (SCL) and inter beat intervals (IBI) were monitored before and after five consecutive nights in two different experimental conditions: 3 min with the instruction to rest and 3 min while providing acoustic stimuli inducing an orienting reflex. Twenty-three participants were recruited for the study, twelve people with insomnia and eleven good sleepers. The selection of the participants consisted in a first screening phase followed by a clinical interview and two weeks of assessment through the use of sleep diaries. Groups were matched for gender and age. Physiological indices were recorded in the participants' own homes through portable devices for one week (weekends excluded), during which sleep–wake cycles were monitored through actigraphic recording and sleep diaries. Sleep Efficiency Index (SEI), obtained as the ratio between total time spent sleeping divided by the total time spent in bed after lights off, was computed for each night. The SEIs were ordered from the worst to the best. Due to technical problems, two participants only had recording for 4 nights. Consequently, one night was excluded for the whole sample. Results showed that the SEI was always higher in good sleepers as opposed to people with insomnia which, moreover, presented higher within subjects and within group variability than did the control group. Regarding the physiological measures, it was found that sympathetic arousal measured by SCLs predicted the quality of the sleep during the subsequent night. Specifically, both groups showed marginally high rest arousal and significantly high arousal in response to stimulation (arousability) linked to low SEI during the subsequent night. The existence of a relationship between sympathetic arousal and sleep quality is consistent with previous results (e.g. Broman, Hetta, 1994). With respect to IBIs results evidenced no systematic
change across both groups and nights of different qualities. In summary, results demonstrated that the variability of sleep quality, which is a central feature of insomnia, is also related to varying levels of evening autonomic arousal and arousability. The same relationship was found also in good sleepers.
Reference Broman, J.E., Hetta, J., 1994. Electrodermal activity in patients with persistent insomnia. J. Sleep Res. 3, 165–170.
doi:10.1016/j.ijpsycho.2008.05.067
A method to map the cortical representation of hand muscle by transcranial magnetic stimulation based on spline interpolation F. Sartucci a, D. Borghetti b, T. Bocci b, E. Petacchi c, A. Guzzetta c, G. Cioni c, L. Murri b a Department of Neuroscience, Pisa University Medical School and Institute of Neuroscience, CNR, Pisa, Italy b Department of Neuroscience, Pisa University Medical School, Pisa, Italy c Department of Developmental Neuroscience, Stella Maris IRCCS, Pisa, Italy Background and objective: To study somatotopic organization of the motor cortex, transcranial magnetic stimulations (TMS) plays nowadays a fundamental role. Aim of our study was to develop and to validate a new method to map the cortical representation of two intrinsic hand muscles (abductor digiti minimi, ADM, and opponent pollicis, OP), using a two dimensional spline interpolation of Electromyographic (EMG) responses peak amplitudes by means of TMS. Methods: Ten healthy volunteers (mean age ± SD: 35.3 ± 4.7 years, 4 males and 6 females) were enrolled. For TMS, a figure-of-eight coil was placed tangentially to the scalp, over a predefined grid drawn on a cap worn by the subject and was subsequently moved from a grid node to another recording the motor evoked responses (MEP) from each node. EMG responses were recorded from right abductor digiti minimi (ADM) and opponent pollicis (OP) muscles. Averaged EMG peak amplitudes obtained at each node and their coordinates were then used to perform spline interpolation using Statistica 6.0® software (StatSoft Inc., USA) and to derive other parameters like Center of Gravity (CoG). Interpolated data were used to calculate fitted peak coordinates and subsequently compared with original parameters with a paired t-test. Results: Arithmetical mean of all resting motor threshold at the hotspot was 50.6 ± 3.4% of the maximal stimulator output; average amplitude was 1.72 ± 0.80 mV and its coordinates, expressed as median, were x = 4.5 cm and y = 0.0 cm. Mean CoG was located at x = 4.86 ± 0.57 cm and y = 0.35 ± 0.10. Mean interpolated peak coordinates for ADM were xf = 4.86 ± 0.58 cm and yf = 0.36 ± 0.12 (p level = not significant versus CoG), while mean fitted peak amplitudes was 0.87 ± 0.47 mV. Averaged amplitudes for each grid's point and their coordinates obtained from ADM and OP were interpolated and subsequently two dimensional mapping of the motor cortex was performed for each subject. Discussion: The present study suggests that is possible to precisely and accurately map the primary motor cortex using two-dimensional spline interpolation of peak to peak amplitudes following multiple TMS, complementary and not substitute to traditional conventional method, useful in the assessment of a wide variety of disorder, either congenital or acquired. Significance: Our methodological study, based on a spline interpolation, results in a smooth, easy to read, amplitude colour-scaled map and allows an easy intra- and inter-subject motor cortex mapping and comparison.
doi:10.1016/j.ijpsycho.2008.05.068
Autonomic changes and stress response in psychopathology C. Pruneti, F. Fontana, C. Fante University of Parma, Department of Psychology, Parma, Italy 89 subjects were consecutively examined into an outpatient clinical centre. The following diagnosis ware made according to the DSM IV - TR
Poster presentations sessions 1,2,3 / International Journal of Psychophysiology 69 (2008) 207–241
criteria1: generalized anxiety disorder (GAD, n = 35), major depression episode (MDE, n = 13), panic attack disorder (PAD, n = 14), obsessive compulsive disorder (OCD, n = 10) Anorexia Nervosa (restricted type) (9). Inclusion exclusion criteria: subjects with physical illness or comorbility with other I or II axis disorders of the DSM IV-TR were excluded. All the subjects underwent a continuous and simultaneous registration of fourth physiological parameters strictly connected with the autonomic arousal: skin conductance response (SCR), heart rate (HR), peripheral temperature (PT) electromyography of the frontal muscle (EMG). All the parameters were continuously registered in three consecutive phases: baseline (registration at rest), stress presentation and recovery. Each phase was 6 minute duration with a stop of 10 s between the phases and 3 min of adaptation before the start of the registration. At the time of the diagnosis all the subjects were free of any medication for at last of three months. Data of the fourth groups of subjects was compared in regard of each of the registered physiological parameters by using the means value of the last minute of the registration at rest, and two activation indexes: stress response” and “recovery after stress”. Furthermore, in each physiological parameters, and for each diagnostic group, mean values in the three different phases (last minute of the rest, first minute of the stress, last minute of the recovery) were compared to evacuate the fourth PPF parameters trend. Statistical tests were utilized to evacuate possible differences into the three phases, and the significance of the changes between one phase and the others. Results from the statistical analysis had shown that in GAD patients and PAD patients, SCR mean values are higher than MDE and OCD (p b .001), the amplitude of the galvanic response is also significantly different (p b .05). Furthermore, the HR response is also higher in GAD than in the other three groups (p b .02). So, OCD and MDE patients seem to be characterized by a flattened profile of all considered parameters. The results suggest an interesting hypothesis of a new tool for the differential diagnosis, represented not only by a single measure as the Skin Conductance as recommended in the DSM IV TR (for the Anxiety Disorder only), but of a specific and typical pattern of autonomic response for some psychopathological syndromes.
doi:10.1016/j.ijpsycho.2008.05.069
Imbalanced activation of the distributed neural system for face perception in social phobia C. Gentili a, M.I. Gobbini b, E. Ricciardi c, N. Vanello d, P. Pietrini c, J.V. Haxby e, M. Guazzelli a a Unit of Clinical Psychology, AUO Pisa, Department of Psychiatry, Neurobiology, Pharmacology, and Biotechnologies, University of Pisa, Pisa, Italy b Department of Psychology, University of Bologna, Bologna, Italy c Laboratory of Clinical Biochemistry and Molecular Biology, Department of Experimental d Department of Information Engineering, University of Pisa, Pisa, Italy e Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NE, US Social Phobia (SP) is a marked and persistent fear of social or performance situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. Human faces are perceived as socially threatening by social phobic patients (SPP). To study how and if face processing is altered in SPP in the distributed neural system for face perception, we designed an fMRI study in which we used an event-related design to present emotional faces (with angry, fearful, disgusted and happy expressions), neutral faces and scrambled pictures (visual baseline). Eight right-handed subjects (4M/4F) (mean age 39 ± 7) with a diagnosis of Social Phobia according to the DSM-IV-TR (APA 2000) criteria and seven right-handed healthy control subjects (4M/3F) (mean age 30 ± 7) were recruited. Consistent with previous reports, we found hyperactivation in SPP, as compared to healthy controls (HC), of regions involved in emotional experience, namely the left amygdala and insula. In addition, we found a stronger response in SPP in the superior temporal sulcus (STS) bilaterally, a part of the core system for face perception that is involved in the appraisal of expression and personal traits. We also found weaker activation of the left fusiform gyrus, left dorsolateral prefrontal cortex and bilateral intraparietal sulcus in SPP. Patients showed augmented processing of information about emotional expression and a stronger and probably wary
225
emotional response to faces. On the other hand activity is decreased in areas for attention and for processing other information from the face, perhaps as a result of this feeling of wariness. These results suggest an imbalance of activity of the distributed neural system for face perception in SPP.
doi:10.1016/j.ijpsycho.2008.05.070
Low-density EEG study of dynamic properties of cortical sleep slow oscillation in humans: Perspectives for clinical applications A. Gemignani a, D. Menicucci b, A. Piarulli a, A. Landi c, U. Olcese c, B. Ghelarducci a, P.D. Ascanio a a University of Pisa, Department of Human Physiology qG. Moruzziq, Pisa, Italy b IFC, CNR, Pisa, Italy c University of Pisa, Department of Electrical Systems and Automation, Pisa, Italy Aim: High-amplitude slow waves with long-range synchrony represent the hallmark of slow wave sleep (SWS) and anesthesia. Intracellular recordings in animals have revealed that during SWS the membrane potential of cortical neurons oscillates between a state of deep hyperpolarization and a state of wake-like depolarization. This cellular behavior, referred to as sleep slow oscillation (SSO), represents the fundamental cellular phenomenon underlying neural activity in SWS. SSO is also detectable in human EEGs and is characterized by typical frequencies less than 1 Hz. Aim of the study is to identify by 32 channels EEG dynamic and spatial features of cortical SSO. Methods: EEG recordings were performed in 8 healthy right-handed male subjects (age 20–25 yrs) during the first sleep cycle of the night. All EOG, ECG and respiratory artifacts were removed by ICA algorithm. Following the approach used by Massimini et al. (J Neurosci, 24:6862-70, 2004), who employed a HiRes EEG (256 channels), each channel was scanned with a sliding window in order to identify all signal shapes with the following features: (a) a negative zero crossing and a subsequent positive zero crossing separated by 0.3–1.0 s, (b) a negative peak between the two zero crossings with voltage less than − 80 μV, (c) a negative-to-positive peakto-peak amplitude N 140 μV. Results: Results indicate that each SSO originates more frequently in frontal scalp regions and propagates over the scalp in a fronto-occipital direction at an averaged speed of 5 m/s. Conclusion: The main findings of this work are 1) our data are consistent with those obtained by Massimini et al., (2004) by HiRes EEG; 2) the results obtained by 40 channels EEG open new possibilities to explore routes of research in different fields of applied neurophysiology and, particularly, of neurophysiopatology.
doi:10.1016/j.ijpsycho.2008.05.071
Perceptual learning of speech processed by a Cochlear Implant simulator — An fMRI investigation G. Rota a,c,f, L. Turicchia b, R. Veit c,d, M. Guazzelli a, N. Birbaumer c,e, G. Dogil f University of Pisa, Department of Psychiatry, Neurobiology, Pharmacology, and Biotechnologies, Pisa, Italy b Massachusetts Institute of Technology, Research Laboratory of Electronics, Cambridge, MA, USA c University of Tuebingen, Institute for Medical Psychology and Behavioural Neurobiology, Tuebingen, Germany d Max Planck Institute for Biological Cybernetics, Tuebingen, Germany e National Institutes of Health, NINDS, Human Cortical Physiology Section, Bethesda, MD, USA f University of Stuttgart, Institute for Natural Language Processing, Stuttgart, Germany
a
Cochlear Implants (CIs) are prosthetic devices that restore hearing in profoundly deaf people. CIs convert sound waves into electrical impulses stimulating the auditory nerve. Newly implanted CI users encounter major difficulties deciphering speech. As time passes, a perceptual learning process induces a modification of the cortical networks that permit speech decoding, resulting in an increased speech intelligibility.