Biomedical subjects

C S Haywood

Publications and source records attributed to C S Haywood.

4 recordsLinked to original sources

PubMed1997

Serial recovery of language during the intracarotid amobarbital procedure.

There is considerable variability among epilepsy centers in the methods and interpretations of the intracarotid amobarbital procedure. Prominent among these differences is the determination of language representation and assessment of language functions. Some centers rely on speech arrest following amobarbital injection as a marker for language representation, whereas other centers examine verbal output for the presence of aphasic errors. The present study assessed the pattern of language recovery following amobarbital injection in epilepsy patients who were candidates for temporal lobectomy. Language recovery from dominant hemisphere injection (left or right) followed a stereotypical progression, with 71.8% of patients showing return of vocalization followed by return of naming and comprehension. Repetition deficits with paraphasic errors persisted the longest (mean = 12'30"), with a conduction aphasia persisting after the acute global aphasia resolved. Although two patients interpreted as left hemisphere language dominant were mute following right hemisphere injection, all language functions were intact immediately upon resumption of vocalization and they showed no other signs of aphasia such as paraphasias or anomia. Possible explanations for serial language recovery and persistent conduction aphasia are discussed. These findings have significant implications for the determination of cerebral language dominance.

Adult↗

PubMed1997

Neuropsychological aspects of facial asymmetry during emotional expression: a review of the normal adult literature.

This review focuses on facial asymmetries during emotional expression. Facial asymmetry is defined as the expression intensity or muscular involvement on one side of the face ("hemiface") relative to the other side and has been used as a behavioral index of hemispheric specialization for facial emotional expression. This paper presents a history of the neuropsychological study of facial asymmetry, originating with Darwin. Both quantitative and qualitative aspects of asymmetry are addressed. Next, neuroanatomical bases for facial expression are elucidated, separately for posed/voluntary and spontaneous/involuntary elicitation conditions. This is followed by a comprehensive review of 49 experiments of facial asymmetry in the adult literature, oriented around emotional valence (pleasantness/unpleasantness), elicitation condition, facial part, social display rules, and demographic factors. Results of this review indicate that the left hemiface is more involved than the right hemiface in the expression of facial emotion. From a neuropsychological perspective, these findings implicate the right cerebral hemisphere as dominant for the facial expression of emotion. In spite of the compelling evidence for right-hemispheric specialization, some data point to the possibility of differential hemispheric involvement as a function of emotional valence.

Adult↗

PubMed1996

Hemispheric specialization for discourse reports of emotional experiences: relationships to demographic, neurological, and perceptual variables.

This study examined hemispheric specialization for discourse reports of emotional and nonemotional experience in 16 right-brain-damaged (RBD), 16 left-brain-damaged (LBD), and 16 demographically-matched normal control (NC) right-handed adults. Patient groups did not differ on etiology, months post-CVA onset, and intrahemispheric lesion location. Subjects were requested to produce monologues about positive and negative emotional and nonemotional experiences. The lexical content of written transcriptions of these monologues was later rated for "emotionality" by naive judges. Overall, RBDs described experiences with less emotional intensity than did NCs and LBDs, providing support for right hemisphere involvement in lexical emotion. Although the RBDs in the current study demonstrated similar patterns of deficits in a prior study [9] on tasks involving lexical emotional perception, there were no significant relationships between the current measures of emotional expression and the previous measures of emotional perception. Finally, the expression and the perception data were examined with respect to intrahemispheric factors. Among the brain-damaged subjects, subcortical structures were more involved in reports of emotional experience, and cortical structures were more involved in the perception of emotion.

Age Factors↗

PubMed1995

Modality dependent changes in event-related potentials correlate with specific cognitive functions in nondemented patients with Parkinson's disease.

The relationship between event-related potentials (ERPs) and cognitive functioning was studied in patients with Parkinson's Disease (PD) but without dementia. Auditory and visual stimuli were used; 30 subjects participated in the auditory study and 20 in the visual study. Patient groups did not differ with respect to gender, age, education, illness duration, and level of cognitive functioning. Visual stimuli were 2.3 cpd sinusoidal grating patterns randomly presented in an oddball paradigm (oblique vs. vertical spatial orientation). Auditory stimuli were tones presented at 70 dB SPL at a rate of 1.1/second, also using the oddball paradigm (1.5K vs. 1K tones). All patients were given neuropsychological tests to measure verbal fluency, memory, visual spatial perception, and abstract reasoning. P300 and N200 abnormalities correlated with a number of these measures, such that longer ERP latencies were related to lower scores on tests of cognitive functioning. Patterns of results suggest that auditory and visual ERPs correlate with different subsets of neuropsychological functions in nondemented PD patients and that N200 may provide a new metric for clinical use.

Cognition↗