Differential Effects of Global Ischemia on Delayed Matching- and Non-Matching-to-Position Tasks in the Water Maze and Skinner Box

In order to assess effects of global ischemia in tasks of spatial learning and working memory, male Wistar rats were subjected to four vessel occlusion (4 VO) for periods of 5, 10, and 20 min and compared with sham-operated controls over four test phases, from 6 to 54 weeks after surgery. Rats were assessed on acquisition in the water maze, a task that is sensitive to ischemic impairments, before testing in Skinner box and water maze working memory tasks, which both require the short-term storage of information, but make different demands on spatial information processing. Phases 1 and 3 assessed spatial learning in a standard water maze procedure (12 and 10 training days, 2 trials/day with a 10-min intertrial interval: ITI). Phase 2 involved training and testing in delayed non-matching-to-position task in the Skinner box, with delays of 2–10 s between the information and choice stages. Phase 4 examined working memory in a water maze delayed matching-to-position task with 4 trials/day, an ITI of 30 s, and a novel platform position on each day. Ischemic rats showed duration-related impairments in water maze acquisition and working memory, but not in the less spatially demanding Skinner box task. Since water maze acquisition deficits were seen both before and after testing in the Skinner box the lack of effect cannot be attributed to time or to prior training. Ischemic deficits were more marked in Phase 3 than in Phase 1 of acquisition, suggesting that impairment may be progressive. Histological assessment showed that cell loss was largely confined to the hippocampal CA1 field and was linearly related to duration of occlusion. At the maximal level of loss (5.7 mm before the interaural line) the 20-min group showed 90% loss, the 10-min group 60% loss, and the 5-min group, which did not differ from controls, less than 10% loss. Only the 20-min group showed significant damage beyond the CA1 field, ranging from 30–40% loss in the CA3 field to 5% loss in one striatal area. No cortical damage was seen. The extent of CA1 cell loss correlated modestly with water maze acquisition (Phase 3) and working memory scores, but not with trials to criterion in the Skinner box task. There were significant correlations between different measures both within and between water maze tasks, but not Skinner box tasks, suggesting that the two types of procedure engaged different cognitive processes. The results indicate that the intrahippocampal damage induced by 4 VO impaired tasks which required processing of allocentric spatial information, but did not impair the storage of limited spatial information in working memory.     

Cognitive functioning and neuroticism in an elderly community sample

The relationship between neuroticism and cognitive functioning was investigated using data from a community survey of the elderly. Contrary to Pearson (1993, Personality and Individual Differences, 14, 265–266), neuroticism was related to poorer performance on a number of cognitive measures, but the pattern of correlations differed between men and women. For men there were correlations with a dementia screening test and with tests of episodic memory and fluid intelligence, while for women there were correlations with reaction time measures. It is hypothesized that correlations with neuroticism reflect the effect of chronic stress on cognitive ageing.     

Some effects of the Edinburgh Masker on stuttering during oral reading and spontaneous speech

This study assessed the effect of a voice-activated masking unit, known as the Edinburgh Masker, on the speech of four stutterers during oral reading and spontaneous speech. The results show that one stutterer reduced stuttering almost completely whenever the masker was activated. Two subjects showed either marginal or temporary reductions of stuttering during one speaking condition but showed no change in the other condition. The other subject reduced stuttering only during spontaneous speech. No reduction in stuttering was associated with reduced speech rate. A perceptual analysis procedure conducted to assess for altered speech quality during masking conditions found changes in speech quality were evident in two subjects. The clinical implications of these findings are discussed.     

Adaptive processing of visual motion

Three studies relating perception of motion to stimulus uncertainty are reported. Generally, detectability declines when the observer is uncertain about the direction in which a target will move, but the visibility loss associated with direction uncertainty can be attenuated if the observer has adequate practice. This attenuation seems to depend upon the observer's ability to switch among directionally selective visual mechanisms in an adaptive fashion. The implications of these findings for models of motion detection are discussed.     

Post-divorce adaptation and the attribution of responsibility

A study was conducted to explore the possible relationship between post-divorce adjustment and the attributions divorced women give for the failure of their marriages. The study revealed that significantly more subjects who attributed their divorces to interactive rather than personal factors were more active, more socially skilled, happier, more optimistic, and less likely to blame themselves rather than outside forces for failures. The findings were also analyzed in light of whether or not subjects had initiated their divorce proceedings. The importance of making interactive attributions was discussed.We would like to thank Cynthia Weinman for her help in conducting the study. We are also grateful to the City University of New York for providing the funds for this research.     

Book reviews

GRAY, J. A. Elements of a Two-Process Theory of Learning. London: Academic Press. 1975. Pp. 423. £6.60.

STOCKBRIDGE, H. C. W. Behaviour and the Physical Environment :Case Studies in Psychology and Ergonomics. London: Batsford. 1975. Pp. 191. £7.50.

CRYSTAL, D. The English Tone of Voice-Essays in Intonation, Prosody and Paralanguage. London: Edward Arnold. 1975. Pp. 198. £3.75.

MCFARLAND, D. J. (Ed.). Motivational Control Systems Analysis. London and New York: Academic Press. 1974. Pp. xii + 523. £11.00.

IVERSEN, S. D. and IVERSEN, L. L. Behavioral Pharmacology. New York and London: Oxford University Press. 1975. Pp. xiv + 310. £2.75.

LEVITT, R. A. Psychopharmacology. A Biological Approach. New York: Wiley. 1975. Pp. x + 502. £9.45.

DOWNS, R. M. and STEA, D. (Eds). Image and Environment. Chicago: Aldine. 1973. (London: Arnold). Pp. xxii + 439. £6.75.

MACCOBY, E. E. and JACKLIN, C. N. The Psychology of Sex Differences. London: Oxford University Press. 1975. Pp. 634. £7.00.

MASSARO, D. W. (Ed.). Understanding Language. New York: Academic Press. 1975. PP. 438. £7.90.

HILGARD, E. R., ATKINSON, R. C., and ATKINSON, R. L. Introduction to Psychology. Sixth Edition. New York: Harcourt Brace Jovanovich. 1975. Pp. 658. £8.10.     

Electrographic correlates of lateral asymmetry in the processing of verbal and nonverbal auditory stimuli

A veraged evoked potentials (AEP) to verbal (digits) and nonverbal (clicks) auditory stimuli were recorded from left and right temporal leads in ten right-handed Ss. With dichotic presentation, there was no significant difference in accuracy of report of the clicks heard in each ear, but significantly more digits were identified correctly from the right ear than from the left. Dichotic verbal stimuli elicited AEP whose early components were of greater amplitude, and whose later components were of shorter latency, from the left hemisphere than from the right. No consistent latency or amplitude differences were observed between AEP from the left and right hemispheres when clicks were presented dichotically.