Human neurobiology最新文献

{"title":"Hemispheric asymmetry in face perception tasks of different cognitive requirement.","authors":"C A Marzi,&nbsp;G Tassinari,&nbsp;P E Tressoldi,&nbsp;C Barry,&nbsp;A Grabowska","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Three laterality experiments using tasks of different cognitive requirement were performed in order to determine the stage at which hemispheric differences in face perception arise. All experiments employed the same set of faces and a vocal reaction time paradigm. In experiment 1, subjects were required to discriminate male from female faces and no hemispheric asymmetries were found. In experiment 2, subjects were required to decide whether or not faces were of famous or unknown people and a right hemisphere advantage was found. Finally, in experiment 3 subjects were required to verbally identify the famous faces and no hemispheric differences were found. The results suggest that a right hemisphere superiority exists for the comparison of stimulus faces with an internal representation. Contrary to expectation, face naming does not result in a selective left hemisphere involvement.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 1","pages":"15-20"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15110098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal organization of behavior.","authors":"J M Fuster","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 2","pages":"57-60"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15143371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Schemas for the temporal organization of behaviour.","authors":"M A Arbib","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Those aspects of the timing of behaviour are emphasized which derive from the need for the organism to coordinate its actions with objects in the environment. Such coordination may require the serial performance of certain actions, yet permit elements of concurrency as well. Perceptual and motor schemas are introduced as units for the functional description of behaviour intermediate between a purely phenomenological description and an account of the detailed neural mechanisms of behaviour. The language of coordinated control programs is outlined to suggest how such schemas are orchestrated in visually and tactilely guided behaviour. Finally, a crucial property of the timing of many movements is discussed: their division into a fast (feedforward, ballistic) phase followed by a slow (feedback) phase. This division is analyzed in the light of the effect of brain damage on reaching movements.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 2","pages":"63-72"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15143373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The percentage of projection neurons and interneurons in the human lateral geniculate nucleus.","authors":"H Braak,&nbsp;A Bachmann","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Projection neurons and local circuit neurons of the human lateral geniculate nucleus (LGN) offer different patterns of lipofuscin pigmentation. One type of projection cell (type I neuron) and two varieties of local circuit neurons (type II and type III neurons) can be distinguished on account of their characteristic pigmentation. The majority of the nerve cells are type I projection neurons. Pigmented type II neurons comprise about 8.5% and type III neurons devoid of pigment amount to only 0.2% of the nerve cells.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 2","pages":"91-5"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15143375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dopaminergic drugs improve human visual contrast sensitivity.","authors":"L Domenici,&nbsp;C Trimarchi,&nbsp;M Piccolino,&nbsp;A Fiorentini,&nbsp;L Maffei","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Effects of dopaminergic drugs (L-dopa plus benserazide, or nomifensine) on human visual function have been tested in healthy volunteers by measuring the psychophysical contrast sensitivity for sinusoidal gratings of various spatial frequencies. After drug administration the contrast sensitivity improved in all subjects over a limited range of medium to high spatial frequencies.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 3","pages":"195-7"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15177895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal tracking and synchronization strategies.","authors":"D Hary,&nbsp;G P Moore","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Timing measures were obtained from subjects instructed to tap a Morse key in synchrony with a metronome which marked a timing pattern consisting of alternating blocks of intervals of imperceptibly different duration. \"Synchronization strategies\", which consisted of computer-simulated sets of rules, or algorithms, hypothesized to be the basis of synchronization behavior, were used to simulate tapping sequences in response to the same metronome sequences. The human and computer-simulated synchronization data were analyzed identically and compared to determine which of the postulated strategies could explain the observed human tapping behavior. The strategies generating timing data statistically indistinguishable from the human data involve a pattern of human-metronome interaction, and a corresponding transfer of information, more complex and subtle than previous investigations had implied.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 2","pages":"73-9"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15143374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Timing function of the frontal cortex in sequential motor and learning tasks.","authors":"L Deecke,&nbsp;H H Kornhuber,&nbsp;W Lang,&nbsp;M Lang,&nbsp;H Schreiber","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The timing aspects of human frontal lobe function are discussed in the light of the results of three experiments on movement-related cerebral potentials. Experiment I is based on use of a sequential tracking task and experiment II a motor learning task; experiment III deals with frontal hemispheric specialisation by comparing self-initiated writing and drawing. The Bereitschaftspotential (BP) preceding voluntary movement is maximum over the supplementary motor area (SMA) for all movements, including finger, toe, speech, and eye movements, regardless of each movement's different localisation in the brain, e.g., motor cortex, temporal lobe, or midbrain. The assumption that all motor events are governed by the primary (rolandic) motor cortex is erroneous. The motor system is widely decentralised. It is only when this decentralization is recognized that the close temporal association between the onset of all movements and the preceding Bereitschaftspotential in the SMA can be understood. A plausible explanation would be that the SMA decides on the starting time of all the various movements. The frontal function of motivation is not a single entity but has several subfunctions. It has to decide what to do, how to do and when to do. The latter is probably the task of the SMA. A comparison of different motivational situations makes this clear. In the usual BP paradigm, such as self-initiated simple finger or eye movements, only the SMA becomes active among all the frontal areas. If, however, motivation is required to modify motor programs in motor learning, as it is in experiment II, the entire convexity of the frontal lobe shows a large surface-negative potential, the amplitude of which reveals a significant positive correlation with the success in learning. On the other hand, in experiment I, which uses a manual pursuit-movement task requiring attention to unpredictable changes in stimulus direction but providing a fixed time for these changes (so that their timing is foreseeable), the SMA shows anticipatory behaviour; it takes the form of a large negative potential which ceases 0.5 s prior to the end of the directed-attention potential over parietooccipital areas. In other words, in this special situation, where the SMA can anticipate the onset of movement, it seems to delegate the final execution of the movement to the cortical area most specialised for it, in this case the parietooccipital cortex. The supervision of the tasks concerning what to do and how to do may be provided mainly by the orbital cortex and the frontolateral cortex, respectively (Kleist 1934).(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 3","pages":"143-54"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15177976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shifts in selective visual attention: towards the underlying neural circuitry.","authors":"C Koch,&nbsp;S Ullman","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Psychophysical and physiological evidence indicates that the visual system of primates and humans has evolved a specialized processing focus moving across the visual scene. This study addresses the question of how simple networks of neuron-like elements can account for a variety of phenomena associated with this shift of selective visual attention. Specifically, we propose the following: (1) A number of elementary features, such as color, orientation, direction of movement, disparity etc. are represented in parallel in different topographical maps, called the early representation. (2) There exists a selective mapping from the early topographic representation into a more central non-topographic representation, such that at any instant the central representation contains the properties of only a single location in the visual scene, the selected location. We suggest that this mapping is the principal expression of early selective visual attention. One function of selective attention is to fuse information from different maps into one coherent whole. (3) Certain selection rules determine which locations will be mapped into the central representation. The major rule, using the conspicuity of locations in the early representation, is implemented using a so-called Winner-Take-All network. Inhibiting the selected location in this network causes an automatic shift towards the next most conspicious location. Additional rules are proximity and similarity preferences. We discuss how these rules can be implemented in neuron-like networks and suggest a possible role for the extensive back-projection from the visual cortex to the LGN.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 4","pages":"219-27"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14952676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Failure to confirm a correlation between electromyogram and final position.","authors":"J Matheson,&nbsp;M Hallett,&nbsp;A Berardelli,&nbsp;R Weinhaus,&nbsp;S Inzucchi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Attempts were made to correlate angular position of the elbow with integrated electromyographic activity of biceps and triceps. Five conditions were studied: isometric co-contraction and immediately after fast flexion, slow flexion, fast extension and slow extension movements. Neither activity of biceps, activity of triceps or the ratio of activities correlated with any of four different angles for these five conditions.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 4","pages":"257-60"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14952677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the perception of time during prolonged temporal isolation.","authors":"J Aschoff","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Unlabelled: </strong>In an underground isolation unit, 42 subjects were living singly for time spans of at least 7 days up to more than a month. Except three who were entrained to 24 h by an externally controlled light-dark cycle (LD), subjects had no time cues and developed free-running circadian rhythms either in self-selected LD-cycles or in constant illumination. Each subject had to give a signal whenever he thought that 1 h had passed. In addition, 30 subjects produced short-time intervals within the range from 10 to 120 s.</p><p><strong>Results: </strong>The 1-h estimates were longer than 1 h, and had a strong positive correlation with the duration of wakefulness alpha as well as with the length of the circadian cycle. The short time estimates were equally distributed between under- and over-estimation of the required interval, and they were neither correlated with the 1-h estimates nor with alpha. It is concluded that long and short time estimates are based on different mechanisms.</p>","PeriodicalId":77724,"journal":{"name":"Human neurobiology","volume":"4 1","pages":"41-52"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15111344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}