- Email: [email protected]
Memory for tonal sequence and timbre: A correlation with familial handedness
Neuroprjchologia. t Pergamon Press
Vol. Ltd.
17. pp. 539 to 512. 1979. Printed in Crc~r
Britain
NOTE MEMORY
FOR
TONAL
SEQUENCE
WITH
FAMILIAL
BRIAN BYRNE and Department
of Psychology,
AND
University (Received
TIMBRE:
A CORRELATION
HANDEDNESS JUDITH
SINCLAIR
of New England, 19 February
Armidale
2351, Australia
1979)
Abstract-Performance on the Seashore subtests, Tonal Memory and Timbre, were measured for male musically naive subjects with left-handed family members (FLH) and those without (non-FLH). Despite the fact that FLH correlates with certain visuo-spatial deficits, FLH subjects were significantly superior on Timbre and marginally superior on Tonal Memory to their non-FLH controls. Thus spatial skills and musical abilities, in males with no musical training, both putatively right hemisphere based, are affected differently by a variable said to indicate diminished cerebral specialization.
SEVERAL years ago one of the present authors reported a failure to find any dependence between handedness pattern, as measured by the Edinburgh Handedness Inventory [I], and musical skill, assessed on the Tonal Memory and Timbre subtests of the Seashore Measures of Musical Talents [2]. The question was asked (a) because of evidence showing depressed scores on visuo-spatial tests among left- and mixed-handers, due putatively to bilateral representation of linguistic function occurring at the expense of normal right hemisphere-based abilities [3,4], and (b), because of the belief that some musical abilities have a right hemisphere basis [5, 61. BYRNE [2] suggested that the fact that mixed-handers did as well as the control (strongly righthanded) group meant that there was no clear parallel between spatial and musical skills in terms of how they are affected by bilateral language representation. The present study was initiated because GILBERT [7] demonstrated that subjects’ handedness did not correlate with a deficit in a visuo-spatial skill (face recognition), but the presence of a left-handed person in a subject’s immediate family did predict poorer face recognition performance. Others have noted that family left-handedness (FLH) can indicate diminished hemispheric specialization (e.g. [8-IO]), regardless of the pattern of personal handedness. Perhaps, then, certain failures to replicate the work of LEVY [3] and MILLER [4] (e.g. [I I, 121) may be attributed to selecting subjects on the wrong basis-personal rather than familial handedness pattern. Gilbert suggested that family rather than personal handedness is the soundest predictor of cerebral ambilaterality, citing several concordant reports. The import of Gilbert’s work for the earlier conclusions about musical skills [2] is that Byrne’s subjects may also have been selected on an inappropriate basis. In the present study performance on Tonal Memory and Timbre of subjects with and without a left-handed family member was examined, the prediction being that the FLH group would perform more poorly than the nonFLH controls. There may have been another problem with the early study. BEVER and CHIARELLO [I31 have shown that it is only among musically naive subjects that evidence of right hemisphere specialization for melody memory is clear. In experienced musicians it seems that the left hemisphere provides the neurological substrate for this activity, probably because the apperceptive approach of such people to musical sequences is analytic. Naive subjects apparently adopt a holistic processing strategy, a style said to characterize right hemisphere function. No data was collected on the musical sophistication of the mixed-handed subjects used by Byrne (or of the controls either). If a reasonable proportion of them were musically skilled, one would not expect to find poorer memory for tonal sequence or timbre. These subjects would presumably use a left-hemisphere-based strategy and consequently not be susceptible to encroachment of linguistic functions onto areas subserving musical ability. Therefore, the present sample was restricted to musically naive subjects. 539
NOTE
540
METHOD Subjects The subjects were selected from 158 first-year psychology students at the University of New England \vho had completed the Edinburgh Handedness Inventory and had provided information on family handedness and on musical skill. Very few female students confessed to being musically naive by our criteria of inability to play an instrument at all and never having had music lessons. Therefore it was necessary to restrict attention to males. It was possible to secure the co-operation of 15 males who had at least one left-handed immediate family member (a parent or sibling classed as left-handed by the subject) and who claimed no musiccll skill. The mean LQ for the group was 27.7, with a range of - IO0 to - 100. As controls, 13 musically naive males with no familial left-handedness were recruited. Mean LQ was 21.6 (ranging also from - 100 to - IOO), not significantly different to the FLH group [/(26) = 0.109, P > 0.901. Both mean LQ’s were lower than one would expect with a large, unselected sample, reflecting a higher than normal proportion of lefthanded and weakly right-handed subjects in these two groups.
Procedure Each subject was tested individually on a verbal IQ test (A.C.E.R. A.L.), and on the Seashore Timbre and Tonal Memory subtests. The Timbre test consists of 50 pairs of items which may or may not differ in harmonic structure, and listeners have to make same dimerent judgments. The items for the Tonal Memory test are three-, four-, and five-note sequences. In a second presentation ofeach sequence one note is changed, and subjects are required to nominate uhich one is diKerent. For this study the interval between paired sequences was increased from approximately I to 4 set (by re-recording the test) because error rates among college students are low [I!]. There are 30 tonal sequence pairs.
RESULTS
AND
DlSCUSSlON
The most striking feature of the data is the reversal of the predicted eKe_ct. Subjects in-the FLH group scored better on both musical tests, significantly in the case of Timbre [XFLH = 41.8, Xnon_FL,, = 37.4, f(26) = 3.647, P c 0.011 and close to significantly for Tonal Memory [respective means are 19.6 and 15.6, r(26) = 1.841, P -. 0.101. The twogroups had almost identical Verbal IQ’s(FLH, 120; non-FLH, 111). What does now seem clear is that if memory for tonal sequence and timbre are right hemisphere functions in musically naive subjects they are not atfected in the same way as visuo-spatial skills are by variables held to predict ambilateral representation of language in the brain. In fact, the results of this study appear to fit with DEUTSCH’S [IJ] recent observation that weakly left-handed people have an advantage in pitch memory over other subjects. Deutsch considers that handedness pattern is a sign of a low degree of hemispheric specialization for language, and that the results of her experiment can possibly be attributed to the existence of dual storage locations for tones (left and right hemispheres) in people with language well represented in both hemispheres. One would then need to assume either that Deutsch’s moderately left-handed subjects had immediate family members who were left-handed, or that both personal and family handedness patterns can independently signify cerebral ambilaterality, neither perfectly. To check on these possibilities, the LQ’s and family handedness of the large initial pool of subjects from whom we selected those for further study were examined. There were 57 subjects in the FLH group and IO1 non-FLH students. The numbers of males and females in the former group were 28 and 29 respectively; the corresponding numbers for the non-FLH group were 44 and 57. The FLH subjects scored lower on LQ than non-FLH (means of t76 and t88), a significant difference [/(156) = 2.823, P < O.Ol]. Thus there is a tendency for FLH subjects to be less strongly lateralized in handedness than non-FLH subjects, and the possibility that the two variables are confounded in most experiments in this field is quite high. It remains to be seen whether an experiment on musical skills which unconfounded personal and family handedness patterns would produce different results for the various subject groups as GILBERT’s [7] has for a visuo-spatial test. The fact that the two groups in this study did not differ significantly in LQ may mean that familial handedness is the crucial factor. It is worth noting that in ANDREWS’ [IO] study of language lateralization and handedness it was familial rather than personal handedness which correlated with the amplitude of right visual field superiority for recognizing certain linguistic stimuli (a family history of left-handedness being associated with less dependence on left hemisphere). Indices of degree of family and personal handedness correlated moderately and significantly in Andrews’ male subjects. The suggestion is, then, that the presence of left-handedness in a subject’s family history is a sign of a low degree of hemispheric specialization for some language functions, and that one can expect to tind superior memory for tonal quality and melodies in these people. Note. however, that cerebral specialization was not directly tested in the present samples, and the conclusion just drawn must remain tentative.
NOTE
541
ItHould be useful to explore, \ia dichotic techniques, hemispheric localization of timbre and tone sequence memory in subjects such as those used in this study. DELTSCH [I-t] hypothesizes that superior tonal memory in weakly sinistral people may be due to the existence of dual storage locations, in left and right hemispheres. Yet others [7, 151 suggest that some right hemisphere functions, including melody discrimination, remain “in place” even m hen language encroaches on the right hemisphere. A resolution of this question would advance our understanding of brain functions underlying some musical skills. ~ckno~lec/genfertrs-This
research
was supported
by a research
grant
from the University
of New England.
REFERENCES the Edinburgh Inventory. ~Veuropsychologin I. OLDFIELD, R. C. The assessment and analysis of handedness: 9,97-113,197l. and musical ability. Br. J. Psycho/. 6s. 279-281, 1974. 2. BYRSE, B. Handedness of the human brain. hir/~c, Loll. 224, 3. LEVY, J. Possible basis for the evolution of lateral specialization 614-615, 1969. the pattern of human ability. Br. J. Psychol. 62, I I l-l 12. 1971. 4 MILLER, E. Handednessand effects in audition. In I,~rerlre,,ri~p/plreri~ Relcrtiotrs mrd Cerebrtrl Do~~rOmm-e,V. B. 5 MILNER, B. Laterality MOUNTCASTLE (Editor). Johns Hopkins, Baltimore, 1962. asymmetry of the brain in dichotic listening. Currex 3, 163-178, 1967. 6. KIMURA, D. Functional perceptual abilities in relation to left-handedness and cerebral lateralization. 7. GILBERT, C. Non-verbal N~,uropsyclrolclgi(I}lvl(jgi~l 15, 779-791) 1977. of right visual half-fields in right-handers for recall of digits presented 8. HISES, D. and SATZ, P. Superiority at varying rates. rVectrups.vclroloyicr9, 21-25, 1971. and left-right diffsrences in auditory and visual per9. ZLJRIF, R. and BRYDEN, M. P. Familial handedness ception. Neuropprychologirr 7, 179-l 87, 1969. correlated with familial handedness. i~‘e’elrropsy~/to/o.~in IO. ANDREWS, R. 1. Aspects of language lateralization 15,769-778. 1977. Il. KUTAS, M., MCCARTHY, G. and DONCHIS, E. DifTerences between sinistrals’ and dextrals’ ability to infer a whole from its parts: a failure to replicate. Ncuropsychologicr 13,455-464, 1975. competency, 12. FENNELL, E., SATZ, P., VA\ DEN ABELL. T., BOWERS, D. and THO~~AS. R. Visuospatial handedness, and cerebral dominance. B,oi/r & Lofrgucrge5, 206-214. 1978. in musicians and non-musicians. Science. 185 13. BEVEK, T. G. and CHIARELLO. R. J. Cerebral dominance 5-37-539, 1974. for the left handed. Scietrce 199,559-560, 1978. 14. DEUTSCH. D. Pitch memory: an advantage asymmetry and strength of manual preference. Correx 7, 236-255, 1971. 15. DEE, H. L. Auditory
on a mesure les performances
aux subtests de Seashore,memoire
tonale et timbre, chet des hommes naIfs du point de we ou sans stock familial de gaucherie
SFG est carrel@ avec certain3 deficits visuo-spatiaux, etaient significativement de faGon marginale SFG. Ainsi,
musical avec
(SFG). En d&pit du fait que le les sujets SFG
supdrieurs sur le test du timbre et sup6rieurs
sur la memoire tonale par rapport aux contrdles non
les habiletes spatiales et les capacites musicales chez les
sujets masculins
sans culture musicale, toutes deux fond&s
sur l'h6misphere droit, sent diff&remment
affect&s
dont on admet qu'elle diminue la specialisation
en principe
par une variable
cerebrale.
NOTE
Deutschsprachige Zusammenfassung: Leistungen in den Seashore Untertests: Tongedachtnls und Klangfarbe wurden gemessen bei mlnnlichen musikalisch unvorgebildeten Probanden mlt (FLH) bzw. ohne (Non-FLH) linkshandigen Famllienangehorigen. Trotz der Tatsache, daQ FLH mit gewissen optisch-raumlichen Deflziten korreliert, waren FLH-Individuen slgnifikant besser als Non-FLH-Kontrollen hlnsichtlich der Klangfarbe und andeutungswelse besser hlnsichtlich der Tonqualitat. Danach werden bei mPnnlichen Personen ohne.musikalische Ubung rlumliche Fahlgkeiten und MusikalitPt - beides vermutlich rechtshemisphlrisch begriindet- in unterschiedlithem MaSe beeinfluBt durch eine Variable, die verminderte cerebrale Spezlalisierung anzeigt.
Vol. Ltd.
17. pp. 539 to 512. 1979. Printed in Crc~r
Britain
NOTE MEMORY
FOR
TONAL
SEQUENCE
WITH
FAMILIAL
BRIAN BYRNE and Department
of Psychology,
AND
University (Received
TIMBRE:
A CORRELATION
HANDEDNESS JUDITH
SINCLAIR
of New England, 19 February
Armidale
2351, Australia
1979)
Abstract-Performance on the Seashore subtests, Tonal Memory and Timbre, were measured for male musically naive subjects with left-handed family members (FLH) and those without (non-FLH). Despite the fact that FLH correlates with certain visuo-spatial deficits, FLH subjects were significantly superior on Timbre and marginally superior on Tonal Memory to their non-FLH controls. Thus spatial skills and musical abilities, in males with no musical training, both putatively right hemisphere based, are affected differently by a variable said to indicate diminished cerebral specialization.
SEVERAL years ago one of the present authors reported a failure to find any dependence between handedness pattern, as measured by the Edinburgh Handedness Inventory [I], and musical skill, assessed on the Tonal Memory and Timbre subtests of the Seashore Measures of Musical Talents [2]. The question was asked (a) because of evidence showing depressed scores on visuo-spatial tests among left- and mixed-handers, due putatively to bilateral representation of linguistic function occurring at the expense of normal right hemisphere-based abilities [3,4], and (b), because of the belief that some musical abilities have a right hemisphere basis [5, 61. BYRNE [2] suggested that the fact that mixed-handers did as well as the control (strongly righthanded) group meant that there was no clear parallel between spatial and musical skills in terms of how they are affected by bilateral language representation. The present study was initiated because GILBERT [7] demonstrated that subjects’ handedness did not correlate with a deficit in a visuo-spatial skill (face recognition), but the presence of a left-handed person in a subject’s immediate family did predict poorer face recognition performance. Others have noted that family left-handedness (FLH) can indicate diminished hemispheric specialization (e.g. [8-IO]), regardless of the pattern of personal handedness. Perhaps, then, certain failures to replicate the work of LEVY [3] and MILLER [4] (e.g. [I I, 121) may be attributed to selecting subjects on the wrong basis-personal rather than familial handedness pattern. Gilbert suggested that family rather than personal handedness is the soundest predictor of cerebral ambilaterality, citing several concordant reports. The import of Gilbert’s work for the earlier conclusions about musical skills [2] is that Byrne’s subjects may also have been selected on an inappropriate basis. In the present study performance on Tonal Memory and Timbre of subjects with and without a left-handed family member was examined, the prediction being that the FLH group would perform more poorly than the nonFLH controls. There may have been another problem with the early study. BEVER and CHIARELLO [I31 have shown that it is only among musically naive subjects that evidence of right hemisphere specialization for melody memory is clear. In experienced musicians it seems that the left hemisphere provides the neurological substrate for this activity, probably because the apperceptive approach of such people to musical sequences is analytic. Naive subjects apparently adopt a holistic processing strategy, a style said to characterize right hemisphere function. No data was collected on the musical sophistication of the mixed-handed subjects used by Byrne (or of the controls either). If a reasonable proportion of them were musically skilled, one would not expect to find poorer memory for tonal sequence or timbre. These subjects would presumably use a left-hemisphere-based strategy and consequently not be susceptible to encroachment of linguistic functions onto areas subserving musical ability. Therefore, the present sample was restricted to musically naive subjects. 539
NOTE
540
METHOD Subjects The subjects were selected from 158 first-year psychology students at the University of New England \vho had completed the Edinburgh Handedness Inventory and had provided information on family handedness and on musical skill. Very few female students confessed to being musically naive by our criteria of inability to play an instrument at all and never having had music lessons. Therefore it was necessary to restrict attention to males. It was possible to secure the co-operation of 15 males who had at least one left-handed immediate family member (a parent or sibling classed as left-handed by the subject) and who claimed no musiccll skill. The mean LQ for the group was 27.7, with a range of - IO0 to - 100. As controls, 13 musically naive males with no familial left-handedness were recruited. Mean LQ was 21.6 (ranging also from - 100 to - IOO), not significantly different to the FLH group [/(26) = 0.109, P > 0.901. Both mean LQ’s were lower than one would expect with a large, unselected sample, reflecting a higher than normal proportion of lefthanded and weakly right-handed subjects in these two groups.
Procedure Each subject was tested individually on a verbal IQ test (A.C.E.R. A.L.), and on the Seashore Timbre and Tonal Memory subtests. The Timbre test consists of 50 pairs of items which may or may not differ in harmonic structure, and listeners have to make same dimerent judgments. The items for the Tonal Memory test are three-, four-, and five-note sequences. In a second presentation ofeach sequence one note is changed, and subjects are required to nominate uhich one is diKerent. For this study the interval between paired sequences was increased from approximately I to 4 set (by re-recording the test) because error rates among college students are low [I!]. There are 30 tonal sequence pairs.
RESULTS
AND
DlSCUSSlON
The most striking feature of the data is the reversal of the predicted eKe_ct. Subjects in-the FLH group scored better on both musical tests, significantly in the case of Timbre [XFLH = 41.8, Xnon_FL,, = 37.4, f(26) = 3.647, P c 0.011 and close to significantly for Tonal Memory [respective means are 19.6 and 15.6, r(26) = 1.841, P -. 0.101. The twogroups had almost identical Verbal IQ’s(FLH, 120; non-FLH, 111). What does now seem clear is that if memory for tonal sequence and timbre are right hemisphere functions in musically naive subjects they are not atfected in the same way as visuo-spatial skills are by variables held to predict ambilateral representation of language in the brain. In fact, the results of this study appear to fit with DEUTSCH’S [IJ] recent observation that weakly left-handed people have an advantage in pitch memory over other subjects. Deutsch considers that handedness pattern is a sign of a low degree of hemispheric specialization for language, and that the results of her experiment can possibly be attributed to the existence of dual storage locations for tones (left and right hemispheres) in people with language well represented in both hemispheres. One would then need to assume either that Deutsch’s moderately left-handed subjects had immediate family members who were left-handed, or that both personal and family handedness patterns can independently signify cerebral ambilaterality, neither perfectly. To check on these possibilities, the LQ’s and family handedness of the large initial pool of subjects from whom we selected those for further study were examined. There were 57 subjects in the FLH group and IO1 non-FLH students. The numbers of males and females in the former group were 28 and 29 respectively; the corresponding numbers for the non-FLH group were 44 and 57. The FLH subjects scored lower on LQ than non-FLH (means of t76 and t88), a significant difference [/(156) = 2.823, P < O.Ol]. Thus there is a tendency for FLH subjects to be less strongly lateralized in handedness than non-FLH subjects, and the possibility that the two variables are confounded in most experiments in this field is quite high. It remains to be seen whether an experiment on musical skills which unconfounded personal and family handedness patterns would produce different results for the various subject groups as GILBERT’s [7] has for a visuo-spatial test. The fact that the two groups in this study did not differ significantly in LQ may mean that familial handedness is the crucial factor. It is worth noting that in ANDREWS’ [IO] study of language lateralization and handedness it was familial rather than personal handedness which correlated with the amplitude of right visual field superiority for recognizing certain linguistic stimuli (a family history of left-handedness being associated with less dependence on left hemisphere). Indices of degree of family and personal handedness correlated moderately and significantly in Andrews’ male subjects. The suggestion is, then, that the presence of left-handedness in a subject’s family history is a sign of a low degree of hemispheric specialization for some language functions, and that one can expect to tind superior memory for tonal quality and melodies in these people. Note. however, that cerebral specialization was not directly tested in the present samples, and the conclusion just drawn must remain tentative.
NOTE
541
ItHould be useful to explore, \ia dichotic techniques, hemispheric localization of timbre and tone sequence memory in subjects such as those used in this study. DELTSCH [I-t] hypothesizes that superior tonal memory in weakly sinistral people may be due to the existence of dual storage locations, in left and right hemispheres. Yet others [7, 151 suggest that some right hemisphere functions, including melody discrimination, remain “in place” even m hen language encroaches on the right hemisphere. A resolution of this question would advance our understanding of brain functions underlying some musical skills. ~ckno~lec/genfertrs-This
research
was supported
by a research
grant
from the University
of New England.
REFERENCES the Edinburgh Inventory. ~Veuropsychologin I. OLDFIELD, R. C. The assessment and analysis of handedness: 9,97-113,197l. and musical ability. Br. J. Psycho/. 6s. 279-281, 1974. 2. BYRSE, B. Handedness of the human brain. hir/~c, Loll. 224, 3. LEVY, J. Possible basis for the evolution of lateral specialization 614-615, 1969. the pattern of human ability. Br. J. Psychol. 62, I I l-l 12. 1971. 4 MILLER, E. Handednessand effects in audition. In I,~rerlre,,ri~p/plreri~ Relcrtiotrs mrd Cerebrtrl Do~~rOmm-e,V. B. 5 MILNER, B. Laterality MOUNTCASTLE (Editor). Johns Hopkins, Baltimore, 1962. asymmetry of the brain in dichotic listening. Currex 3, 163-178, 1967. 6. KIMURA, D. Functional perceptual abilities in relation to left-handedness and cerebral lateralization. 7. GILBERT, C. Non-verbal N~,uropsyclrolclgi(I}lvl(jgi~l 15, 779-791) 1977. of right visual half-fields in right-handers for recall of digits presented 8. HISES, D. and SATZ, P. Superiority at varying rates. rVectrups.vclroloyicr9, 21-25, 1971. and left-right diffsrences in auditory and visual per9. ZLJRIF, R. and BRYDEN, M. P. Familial handedness ception. Neuropprychologirr 7, 179-l 87, 1969. correlated with familial handedness. i~‘e’elrropsy~/to/o.~in IO. ANDREWS, R. 1. Aspects of language lateralization 15,769-778. 1977. Il. KUTAS, M., MCCARTHY, G. and DONCHIS, E. DifTerences between sinistrals’ and dextrals’ ability to infer a whole from its parts: a failure to replicate. Ncuropsychologicr 13,455-464, 1975. competency, 12. FENNELL, E., SATZ, P., VA\ DEN ABELL. T., BOWERS, D. and THO~~AS. R. Visuospatial handedness, and cerebral dominance. B,oi/r & Lofrgucrge5, 206-214. 1978. in musicians and non-musicians. Science. 185 13. BEVEK, T. G. and CHIARELLO. R. J. Cerebral dominance 5-37-539, 1974. for the left handed. Scietrce 199,559-560, 1978. 14. DEUTSCH. D. Pitch memory: an advantage asymmetry and strength of manual preference. Correx 7, 236-255, 1971. 15. DEE, H. L. Auditory
on a mesure les performances
aux subtests de Seashore,memoire
tonale et timbre, chet des hommes naIfs du point de we ou sans stock familial de gaucherie
SFG est carrel@ avec certain3 deficits visuo-spatiaux, etaient significativement de faGon marginale SFG. Ainsi,
musical avec
(SFG). En d&pit du fait que le les sujets SFG
supdrieurs sur le test du timbre et sup6rieurs
sur la memoire tonale par rapport aux contrdles non
les habiletes spatiales et les capacites musicales chez les
sujets masculins
sans culture musicale, toutes deux fond&s
sur l'h6misphere droit, sent diff&remment
affect&s
dont on admet qu'elle diminue la specialisation
en principe
par une variable
cerebrale.
NOTE
Deutschsprachige Zusammenfassung: Leistungen in den Seashore Untertests: Tongedachtnls und Klangfarbe wurden gemessen bei mlnnlichen musikalisch unvorgebildeten Probanden mlt (FLH) bzw. ohne (Non-FLH) linkshandigen Famllienangehorigen. Trotz der Tatsache, daQ FLH mit gewissen optisch-raumlichen Deflziten korreliert, waren FLH-Individuen slgnifikant besser als Non-FLH-Kontrollen hlnsichtlich der Klangfarbe und andeutungswelse besser hlnsichtlich der Tonqualitat. Danach werden bei mPnnlichen Personen ohne.musikalische Ubung rlumliche Fahlgkeiten und MusikalitPt - beides vermutlich rechtshemisphlrisch begriindet- in unterschiedlithem MaSe beeinfluBt durch eine Variable, die verminderte cerebrale Spezlalisierung anzeigt.