Denis M. Parker

A handbook of neuropsychological assessment

J. Crawford, D. Parker, Introduction. E. Miller, Some Basic Principles of Neuropsychological Assessment. J. Crawford, Current and Premorbid Intelligence Measures in Neuropsychological Assessment. M. Annett, Assessment of Laterality. A. Mayes, R, Warburg, Memory Assessment in Clinical Practice and Research. A. Hickox, Dr. A. Sunderland, Questionnaire and Checklist Approaches to Assessment of Everyday Memory Problems. J.G. Beaumont, J.B. Davidoff, Assessment of Visuo-Perceptual Dysfunction. H.D. Ellis, Assessments of Deficits in Facial Processing. P. Halligan, I.H. Robertson, The Assessment of Unilateral Neglect. S. Walker, Assessment of Language Dysfunction. P.H.K. Seymour, The Assessment of Reading Disorders. A.H. van Zomeren, W.H. Brouwer, Assessment of Attention. D.M. Parker, J. Crawford, Assessment of Frontal Lobe Dysfunction. R.G. Morris, M.D. Kopelman, The Neuropsychological Assessment of Dementia. J.T.L. Wilson, K.D. Wiedmann, Neuropsychological Assessment in Alcohol and Drug Abuse and Toxic Conditions. C. Skilbeck, Neuropsychological Assessment in Stroke. W.W. McKinlay, J.M. Gray, Assessment of the Severely Head Injured. W.W. McKinlay, Assessment of the Head Injured for Compensation. M.D. Rugg, Event-Related Potentials in Clinical Neuropsychology. S.L. Wilson, T.M. McMillan, Computer-Based Assessment in Neuropsychology.

Latency changes in the human visual evoked response to sinusoidal gratings.

Abstract Averaged potentials evoked by the presentation of sine wave gratings of different spatial frequencies were recorded from the human scalp. Results indicated a progressive delay in peak latency of all negative and positive waves generated by stimulus onset as spatial frequency was increased although this trend was clearer in the early N(90–140) and P(140–180) than in the late N(180–200) and P(255–275) waves. These results are discussed in relation to psychophysical studies which indicate delays in simple reaction time to sinusoidal gratings as spatial frequency is increased.

Spatial Content and Spatial Quantisation Effects in Face Recognition

It has recently become apparent that if face images are degraded by spatial quantisation, or block averaging, there is a nonlinear acceleration of the decline in accuracy of recognition as block size increases. This suggests recognition requires a critical minimum range of object spatial frequencies. Two experiments were performed to clarify the phenomenon. In experiment 1, the speed and accuracy of recognition for six frontoparallel photographs of faces were measured. After familiarisation training sessions, the images were shown for 100 ms with 11, 21, and 42 pixels per face, horizontally measured. Transformations calculated to remove the same range of spatial frequencies were performed by means of quantisation, a Fourier low-pass filter, and Gaussian blurring. Although accuracy declined and speed increased in a significant, nonlinear manner in all cases as the image quality was reduced, it did so at a faster rate for the quantised images. In experiment 2, faces rated as being typical were shown at 9, 12, 23, and 45 pixels per face and with appropriate Fourier low-pass versions. The nonlinear decline was confirmed and it was shown that it could not be attributed to a ceiling effect. A further condition allowed quantised and Fourier low-pass conditions to be compared with an unstructured-noise condition of equal strength to that of the quantised images. These gave comparable, but slightly less impaired, recognition than the quantised images. It can be inferred from these results that the removal of a critical range of at least 8–16 cycles per face of information explains the step decline in recognition seen with quantised images. However, the decline found with quantised images is reinforced by internal masking from pixelisation.

Simple reaction times to the onset, onset, and contrast reversal of sinusoidal grating stimuli

Response latencies to the onset, offset, and contrast reversal of sinusoidal gratings over a range of spatial frequencies were measured. For gratings of constant physical contrast, RT was monotonically related to spatial frequency regardless of presentation mode. Comparison of RTs to 1.0- and 9.0-cycle/deg gratings adjusted to equal apparent contrast showed that the RT shifts cannot be directly attributed to contrast sensitivity differences. It is concluded that spatial-frequency-dependent processing delays occur regardless of which temporal property of the stimulus the subject must respond to.

The Spatial Selectivity of Early and Late Waves within the Human Visual Evoked Response

Two studies on the amplitude, latency, and waveform of human visual evoked responses to the onset of sine-wave grating patterns were made. Results indicated that the peak latencies of both early and late waves were a function of the spatial frequency of the stimulus. The amplitude of the early wave (N1−P1) was consistently greatest at low spatial frequencies while the late wave (N2−P2) showed consistent attenuation at low spatial frequencies. In addition the location of the peak amplitude response of the late, but not the early, wave depended on the location (macular versus extramacular) and area (small versus large stimulus field) of retina stimulated. These findings are discussed in the light of evidence for separate transient and sustained systems within the human visual system.

A forebrain lesion preventing imprinting in domestic chicks

SummaryNewly hatched domestic chicks were subjected to bilateral aspiration lesions of the anterior, dorsal, posterior or lateral regions of the forebrain and then were reared separately with one of two types of imprinting object. Between 3 and 10 days later they were tested for imprinting, pecking accuracy, visual looming and auditory startle responses. Lateral and dorsal lesion groups differed from a control group in the number of successful discriminations of their imprinting object and the lateral group was not significantly different from a random expectancy. All groups were impaired in pecking accuracy but the lateral group was the most severely affected. Looming responses and post startle freezing behaviour were reduced only in the posterior and dorsal groups which were also the least responsive in the imprinting tests. It was concluded that the lateral forebrain area is critically and specifically involved in the visual learning of imprinting being necessary for the discrimination of, but not for approach responsiveness to, imprinting objects.

Construct validity of the National Adult Reading Test: a factor analytic study

Abstract Factor analysis was carried out on the National Adult Reading Test (NART) and Wechsler Adult Intelligence Scale (WAIS) performance of 139 normal subjects. The NART loaded very highly on factor I extracted by principal components analysis (PCA), suggesting that the NART has high construct validity as a measure of general intelligence. Varimax rotation of the three factors extracted by PCA produced a factor structure that was consistent with previous factor analytic studies of the WAIS. The NART loaded highly on Factor I (verbal intelligence) but not on Factor II (non-verbal intelligence) or Factor III (attention/concentration).

Perceptual latency and spatial frequency.

Subjects estimated the perceived onset of sinusoidal gratings by adjusting a visual probe so that grating and probe were phenomenally simultaneous. The first experiment found that perceptual latency increased by an average of 21 msec over a range of 0.5-9.0 c/deg, or approximately 5 msec per octave of spatial frequency. A second experiment found, that when a fundamental frequency and its third harmonic at one third contrast are compared, a lag of between 21 and 25 msec for the higher frequency lower amplitude grating is obtained. These spatial frequency dependent delays are substantially lower than those reported using other methods.

Role of coarse and fine spatial information in face and object processing.

In 4 experiments the role of coarse (low-pass filtered) and fine (high-pass filtered) spatial information in guiding visual processing was studied in a same-different task. The second of a pair of sequential patterns was either a normal image or the first 100 ms was restricted either coarse or fine information before a normal image was shown for the rest of the presentation. This 100-ms cue could be from the immediately succeeding image (relevant) or from other images in the set (irrelevant). Analysis of response times and errors showed relevant coarse- and fine-scale cues were usually equally effective, but any differences favored fine-scale versions. Irrelevant fine-scale cuing was significantly more disruptive than coarse-scale cuing. No evidence of preferential cuing by coarse-scale information occurred in any experiment.

Developments in clinical and experimental neuropsychology

Brain Imaging Techniques in Alzheimers Disease (CT, NMR, SPECT and PET).- Dementia: Cerebral Blood Flow (SPECT) Correlates of Cognitive Impairment.- Neuropsychology and Neuroimaging after Traumatic Brain Damage.- Cognitive Dysfunction in Latent Portasystemic Encephalopathy.- Effects of Essential Fatty Acid Supplementation on Neuropsychological Function in Abstinent Alcoholics.- Estimation of Premorbid Intelligence: A Review of Recent Developments.- Language in Dementia of the Alzheimer Type.- Patterns of Hemispheric Asymmetry Set Against Clinical Evidence.- Interhemispheric Transmission Times.- Divided Visual Field Studies in Schizophrenia.- Late Positive Event Related Potentials in Schizophrenia.- Electrophysiological Correlates of Facial Identity and Expression Processing.- Past and Recent Studies of Prosopagnosia.- Different Forms of Face-Knowledge Impairment.- Human Organic Memory Disorders: Problems and Interpretations.- Anarthria and Verbal Short-Term Memory.- Retrograde Amnesia in Korsakoffs Syndrome: An Experimental and Theoretical Analysis.- Reys Auditory Verbal Learning Test - A Review.- Measuring Memory Impairment After Brain Damage: The Influence of Perceptual Problems.- Investigative Methods in Paediatric Neuropsychology.- Attention, Children and Head Injury.- Temporal Lobectomy, Cognition and Behaviour: A Brief Review with Special Reference to the Requirements of Informed Consent.- Dysphasia Therapy: A Respectable Occupation?.- Family Based Memory Rehabilitation After Traumatic Brain Injury.- Neuropsychological Causes for Agoraphobia.- Neuropsychological Evidence for Localisation of Visual Sensory Functions.- Inspection Time: Experimental Advances and Clinical Prospects.- Addresses of Principal Authors.