Multisensory integration of amplitude modulated auditory and tactile stimulation as revealed by steady-state responses

Multisensory integration of amplitude modulated auditory and tactile stimulation as revealed by steady-state responses

376 Poster Abstracts / International Journal of Psychophysiology 85 (2012) 361–430 emotional state on the Positive and Negative Affective Schedule (...

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376

Poster Abstracts / International Journal of Psychophysiology 85 (2012) 361–430

emotional state on the Positive and Negative Affective Schedule (Watson and Clark, 1994). Data related to peripheral psychophysiological activity was recorded on five channels: ECG, EDA, respiratory frequency and two facial EMG channels (with electrodes placed on the Corrugator Supercilii and Zygomaticus Major muscles). In the first phase of the experiment, participants watched a random series of 70 pictures (7 s each) representing human faces, each one showing 1 out of 5 emotional expressions (fear, disgust, anger, happiness and neutral; extracted from Ekman and Friesen's Pictures of Facial Affect), with the sole instruction to pay attention to the presented pictures. In the second phase, the participants watched the same set of pictures in a random order but with the explicit instruction to try to mimic the emotional expression of the faces in the pictures. Primary analysis of psychophysiological data revealed that socially anxious participants experienced higher arousal than controls when looking at faces depicting emotions with negative valence in both conditions of the experiment (phasic EDA, look instruction: t(49) = 5.32, p b .001; phasic EDA instruction to mimic: t(49) = 3.98, p b .001). Also, they were less able to mimic the emotional expression for these emotions (facial EMG activity, look instruction t(49) = − 4.38, p b .001; facial EMG, instruction to mimic t(49) = −4.08, p b .001) but were similar to controls for the positive ones (look instruction: t(49) = 1.27, p = .210; instruction to mimic: t(49) = −1.44, p = .156). Interestingly, in a secondary analysis, both self-focused attention and dysfunctional appraisal measures moderated the mimicry expressed by socially anxious and healthy controls (look instruction: F(1,48) = 5.32 p = .025 and F(1,48) = 6.01, p = .017; instruction to mimic: F(1, 48) = 4.98; p = .030, F = (1,48) = 5.20, p = .027). We found preliminary evidence that social anxiety might impair the capacity to empathize with the negative emotion expressed by others through facial expressions. Yet, the mechanism through which this impairment occurs seems to be more complex than the ones described by the theories from which we derived our predictions. Both pathways that we tested in this study (i.e. the moderating roles of self-focused attention and dysfunctional appraisals) contributed in explaining the imitation of facial mimicry in our participants. A comprehensive explanation for these results is discussed.

doi:10.1016/j.ijpsycho.2012.07.035

Endocrine determinants of the formation of character traits in men with a criminal stereotype behavior

Research was carried out in the conditions of natural experiment. The main group that was surveyed was made up of 105 men of 21– 35 years who were the prisoners of Stavropoulos prison No. 5 of a general regime, condemned on article 105 of the criminal codes of Russian Federation, murder. In the control group there were students of Stavropol State University (89 men) at the age of 21–22 years. We used methods of psychological testing: technique of definition of level of a neurotization and psychopatization (Bazhin E., 1976), Buss– Durkee questionnaire (1998), scale of manifestation of uneasiness (J. Taylor, 1953), Eysenck's personal questionnaire (1973); physiological definition of level of steroid (cortisol — C, testosterone — T, estradiol — E) and thyroid (tiroxin — T4) hormones in a saliva by the method of immune-ferment analyses on device “Pikon”. The index of androgenization (our term) was counted (Т/E ratio). The obtained data were processed statistically. Research of the endocrine status of the men condemned for murder, showed that concentration of C at them considerably varied and averaged 15.8± 2.0 nmol/l (in control group — 18.2 ± 0,9 nmol/l). Considerable variability of the content of C in saliva of condemned for murder allowed us to divide groups surveyed into three subgroups: 1) with high (27.6 ± 2.1 nmol/l); 2) with average (13.6 ± 0.9 nmol/l); 3) with low (3.8 ± 0.5 nmol/l) level of C in saliva. The lowest level was found in men with high level of C. The level of E at condemned for murder was lower, than in control group. In subgroups the level of E did not differ essentially. At the reduced absolute sizes of androgen estrogen level, the men condemned for murder, had an index of an androgenization (T/E) authentically higher than the men of the control group. Thus the relation C/T at condemned for murder considerably (in 1.7 times) exceeded such indicator of men in control group. The most significant distinctions were revealed at men with high and low level of C. The content of T4 in a sativa of the men condemned for murder was lower than the control group (67.7 ± 2.9 nmol/l and 77.0 ± 2.0 nmol/l respectively; p b 0.05), and ratio T4/T authentically exceeded such indicator at men of control group (p b 0.05). The correlation analysis showed that violation of the endocrine status determines neurotization and psychopatization level, uneasiness level, the size of an index of aggression, the level of physical and verbal aggression, irritability and suspiciousness, offense and sense of guilt (r = 0.30 ÷ 0.80). The greatest number of correlation dependences is found between ratio of androgens and estrogens, catabolic and anabolic hormones. The results of the research suggest that the high probability of phenotype variability of personnel properties and characteristic lines in individuals with a criminal stereotype behavior is caused by violation of an endocrine profile of the steroid (sexual and glucocorticoid) and thyroid hormones.

E.V. Buhantsovaa, L.I. Gubarevaa, O.A. Achverdovab Department of Psychophysiology, State University, Pushkin street 1, Stavropol, Russia b Department of Clinical Psychology, State University, Pushkin street 1, Stavropol, Russia

doi:10.1016/j.ijpsycho.2012.07.036

For the last 15–20 years in Russia the crime rate has grown and become more serious and socially dangerous. Its new forms have appeared and are developing (Gurov A.I., 1990). Today the highest crime is registered in the richest economically, socially and politically developed countries and we regard that at the heart of the formation of criminal behavior lie not only social and economic, but also biological factors. However the question of the role of biological factors in formation of a criminal behavior has not been finally solved. The purpose of this work was the study of features of the endocrine status, determining the formation of characteristic lines and properties of the personality of men with a criminal stereotype behavior.

T.W. Budd School of Psychology, University of Newcastle, Australia

a

Multisensory integration of amplitude modulated auditory and tactile stimulation as revealed by steady-state responses

Multisensory integration (MSI) has traditionally been characterised as a process occurring subsequent to initial unimodal sensory processing and involving higher order association cortices. Recent research has provided evidence that MSI occurs at the very earliest stages of sensory processing and in primary sensory regions thought to be exclusively unimodal. These studies employ superadditivity to measure MSI, where event-related responses (ERP) to multimodal stimuli exceed the algebraic sum of the responses to the corresponding unimodal stimulation (Foxe et al., 2000). Prior EEG

Poster Abstracts / International Journal of Psychophysiology 85 (2012) 361–430

research has demonstrated that EEG entrainment to periodic stimulation is modality specific. For the somatosensory modality the maximum steady-state responses (SSR) are elicited by stimulation rates between 21 and 26 Hz (Tobimatsu, Zhang & Kato, 1999), whereas for the auditory modality the maximum SSRs are elicited by 40 Hz stimulation (Picton et al. 1987). The primary aim of this study was to determine if; a) whether the entrainment of EEG to multimodal stimuli as measured by the SSR differs from the SSR to the corresponding unimodal stimuli b) whether the SSR to multimodal stimuli demonstrates superadditivity as previously found for ERP response to multimodal stimuli. Auditory and vibrotactile stimuli were created using a broadband noise carrier (0–4 kHz for auditory; 0–256 Hz for vibrotactile; 1500 ms duration) and sinusoidally amplitude modulated at one of eight modulation rates (2, 4, 8, 16, 24, 32, 40 and 64 Hz) for each of three different stimulus conditions (auditory; somatosensory or simultaneous). During two consecutive 45 min EEG recording sessions auditory stimuli were presented binaurally over headphones at 80 dB (SPL) and vibrotactile stimuli were delivered bimanually using piezoelectric benders to the index finger. Following prior studies, super-additivity was measured by comparing Simultaneous with Summed (sum of auditory and vibrotactile) ERPs for each of the eight modulation rates. N1 ERP peak amplitude and SSR responses (evoked power) were measured separately for each of the eight modulation rates. The N1 ERP amplitude showed a significant curvilinear function of modulation rate for both auditory and vibrotactile stimuli and demonstrated superadditivity as N1 responses were significantly greater in the Simultaneous relative to the Summed condition. EEG entrainment as revealed in SSR power was confined to stimulus modulation rates of 16 Hz or greater where, auditory SSR responses were greater at 40 Hz and vibrotactile SSER responses at 24 Hz modulation rates. Superadditivity was evident as increased SSR responses to 40 and 24 Hz SSRs for Simultaneous relative to Summed SSR responses as well as the significantly increased SSR power in the 8 Hz and 40 Hz EEG frequency bands for Simultaneous auditory and vibrotactile stimulation. The present results support prior ERP research indicating that MSI (superadditivity) is evident at an early stage of sensory processing (N1 peak activity). The SSR results also replicate prior unimodal SSR studies showing modality specific entrainment to periodic stimulation as well as providing evidence that super additivity can be observed in the entrained SSR to amplitude modulated auditory and somatosensory stimulation. The present results provide new evidence that the SSR measures resolve rhythmic EEG activity that are only apparent during multimodal stimulation, suggesting the SSR may provide a sensitive measure of MSI of temporally dynamic sensory stimuli.

doi:10.1016/j.ijpsycho.2012.07.037

Differences in brain network associated with the degree of impulsivity J. W. Seoka, H.E. Kima, J.S. Eomb, J.H. Sohna Department of Psychology, Brain Research Institute, Chungnam National University, Daejeon, South Korea b Department of Psychology, Chungbuk National University, CheongJu, South Korea

a

Impulsivity is a multidimensional concept that incorporates failure of response inhibition, rapid processing of information, novelty seeking, and inability to delay gratification (Barratt, 1985,

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1994). While numerous studies have focused on structural and taskbased functional magnetic resonance imaging related to impulsivity, few studies have explored resting-state brain activity in relation to impulsive trait. The purpose of this study was to examine differences in brain network across different levels of impulsivity. Eleven male adults with high impulsivity (BIS scoring greater than 15 points), and eleven same-age males with low impulsivity (BIS scoring less than 7 points) were scanned using resting-state functional magnetic resonance imaging (fMRI). For the connectivity analysis, regions of interests (ROIs) were defined based on previous impulsivity studies, including the inferior parietal cortex (IPC), cingulate gyrus, caudate nucleus, putamen, orbito frontal cortex (OFC), dorsolateral prefrontal cortex (DLPFC), and insula. Functional connectivity assessment for each subject was obtained by correlating time-series across the ROIS, resulting in 7 × 7 matrix for each subject. Within-group functional connectivity patterns were observed by entering the z maps of the ROIs of each subject into the second-level one sample t-test. Two sample t-test was also performed to examine between group differences. A significant increase was observed in positive functional connectivity between the DLPFC and several brain regions, including the OFC, cingulated gyrus (FDR, p b 0.05) in low-impulsive group. However, no significant correlations in these structural connectivities were found in high-impulsive group. Low-impulsive group presented significant positive connectivity between the insula and putamen (FDR, p b 0.05). Compared with low-impulsive group, high-impulsive group showed increased connectivity between insula and putamen (FDR, p b 0.05). Results showed significant differences in the patterns of functional connectivity between high-impulsive group and low-impulsive group during resting-state fMRI. More specifically, compared to highimpulsive group, the low-impulsive group exhibited greater restingstate brain activities in DLPFC, area known to be associated with the control of impulsive behaviour (Gian et al, 2008).

doi:10.1016/j.ijpsycho.2012.07.038

Stop paradigm in attention deficit hyperactivity disorder combined type (ADHD/C) children: A study with event related potentials (ERP) G. Yáñez, H. Romero, J. Bernal, V. Guerrero, E. Marosi, B. Prieto, M. Rodríguez, J. Silva National University of México, FES Iztacala, México Recently, deficiency in behavioral inhibition (BI) has been reported in the literature that underlies many symptoms of ADHD/C. The objective of this work was to study the BI through the stop paradigm which measures the inhibition of an ongoing response during recording ERP in children with ADHD/C. A sample of 26 boys between 7 and 12 years was selected with the Conner's Scale and WISC-R for this study, 13 of them with ADHD/C and 13 control children. We used a go/go paradigm with a stop signal with delays of 200, 300, 400 and 500 ms. Total IQ had no significant differences between groups, neither in early components (N200, P200). We observed a positive component between 300 and 400 ms in frontal regions that had significantly lower amplitude for all delays in the group with ADHD/C. These results make evident that children with ADHD/C have a deficit in behavioral inhibition, which is reflected only at frontal regions.

doi:10.1016/j.ijpsycho.2012.07.039