Dennis H. Holding

Extremely long-term persistence of the McCollough effect

The question has been raised whether an associative mechanism is responsible for the persistence of the McCollough effect. Since current estimates of its rate of decay are derived from procedures in which subjects are repeatedly tested, it was hypothesized that the measured effects might be attenuated by the testing process. Accordingly, a comparison was made between repeated testing and time-elapse testing. A conventional group of 16 subjects had repeated testing at 0, 8, 24, 56, and 120 hr. after induction. Five other groups of 16 were run, each at one of the time delays, with no intervening tests; an additional measure was taken where appropriate at 120 hr. A magenta-green nulling procedure was used to assess the aftereffect. The repeated-test group showed a linear decrease of effect against the stated delays, reaching zero at 120 hr. In contrast, the time-elapse groups showed little decline up to 120 hr. Those groups retested at 120 hr. showed declines due to prior testing. When four more groups were subsequently tested at intervals up to 2,040 hr., the effect remained at better than half strength.

Acquisition of Route Network Knowledge by Males and Females

Abstract Male and female subjects were tested for spatial ability and were shown slides depicting pairs of intersecting suburban routes. They saw each route either one or three times. Pairs of test slides were then presented, and measures were taken of the judged angle and direct distance between the two scenes as well as of the time taken to make the judgment. In addition, subjects made judgments of the travel distances and placed target locations on a sketch map of the route network. The crucial comparison was between those judgments made across routes and those made within routes. Because these did not differ, it appeared that network knowledge had been acquired during original learning. Males were more accurate than females in angular judgment and in travel distance estimation. Further analysis of the angular estimates, using circular statistics, illustrated a tendency for females to underestimate the wider angles. The correlations between the various measures of spatial ability were low, suggesting t...

Sensory storage reconsidered

Models of sensory storage appear to incorporate three features: capacity in excess of short-term memory, rapid decay of information, and an unprocessed trace as the storage medium. The evidence for each is examined in the visual and the auditory modes. The excess capacity hypothesis is rejected on the grounds that negative results are obtained when output interference and cue anticipation mechanisms are excluded. Rapid decay is seen as a minor effect which may not result from sensory storage. Limited trace storage appears to exist in the form of extremely brief sensory persistence, but applies only to normally attended stimuli; the pivotal concept of subsequent random access to a trace appears unsupported.

Theories of chess skill

SummaryThe paper reviews the evidence for and against the recognition-association theory and a forward-search (SEEK) theory of chess skill. The recognition-association theory appears to be founded on indirect evidence concerning visual short-term memory, together with supplementary assumptions that may be questioned, and provides no role for verbal processes. There is no direct support for the theory, which omits forward search for reasons that are reexamined. In contrast, the SEEK theory maintains that move choice is based on search and evaluation processes supplemented (or else supplanted) by a knowledge base. These processes are directly evidenced by experimental findings. The objection that search theories cannot account for speed chess is met by a review of the available evidence. It is concluded that chess skill relies on thinking ahead rather than on pattern recognition.

Recall or evaluation of chess positions as determinants of chess skill

Previous research has found that the ability to recall briefly presented chess positions varies with playing strength, except when random positions are used. The suggestion therefore arises that mastery consists of recognizing configurations that are associated with plausible moves. This approach is tested by comparing the memory scores and move-choice protocols of players in six skill categories, using random chess positions. Contrary to any strong form of recognition-association hypothesis, differences in chess skill are shown to persist although memory differences are abolished. It is further shown that the moves selected are not based on those few pieces that are remembered. Skill-related differences in the accuracy of positional evaluations also occur, but they are less marked than in earlier results. An alternative approach to chess skill seems appropriate, in which memory effects may function at the evaluation phase.

The amount seen in brief exposures.

The experiments reported are a series of attempts to test the consequences of assuming that a subject exposed to briefly presented tachistoscopic information does not have access to a visual image. The partial report procedure is examined under several conditions with the letter row cues immediately following stimulus exposure, and at different levels of cue delay. The results of eye movement monitoring, and of instructing subjects where to look, agree with the guessing data of a previous experiment in showing a sharp decline in the number of letters correctly reported when the subject is looking at the wrong row, in conformity with the anticipative selection hypothesis. The result of varying the subjects uncertainty about what is to be reported is to vary the slope of the delay curve; with the implication that inefficient strategies of rehearsal, rather than visual image decay, are responsible for the reported delay effects.

Brief visual memory for English and Arabic letters

American and Arabic Ss were asked to make whole and partial reports on briefly presented letter arrays in English and Arabic script. None of the ratios between whole and partial report suggests the availability of excess sensory storage. For the Arab Ss, who were bilingual to varying degrees, comparison of the scripts was ambiguous. The American Ss had access to over three familiar letters in whole report, as expected, but were able to report less than one of the Arabic symbols. These results appear counter to the visual storage hypothesis.

Personal memories at different ages

Men and women aged between 25 and 75 were asked to associate personal experiences to a set of 50 randomly chosen common words. The dates of these experiences were reconstructed and plotted as frequency distributions. Neither sex differences nor introversion—extraversion had reliable effects, and response latencies did not differ between conditions, but age differences significantly affected the memory distributions. Contrary to the hypothesis that ageing produces a selective deficit for recency, it appears that the average date of remembered events tends to increase with age.

The Effects of Noise and Speech on Cognitive Task Performance

In the present study, which is based on Loebs 1986 analysis, we used five levels of noise that varied in intermittency and meaningfulness, crossed with sex of subject and time of day. Memory tasks that differed in their reliance upon long-term, short-term free recall, and sequential short-term memory were used as dependent variables. A total of 160 subjects, 20 per block, participated in the 2 x 2 x 5 (Sexes x Time of Day x Noise Conditions) experimental design. Results support the prediction that white noise enhances performance on tasks with sequential short-term memory demands (anagrams: p < .05; random letter generation: p < .002). We found complex interactions by sex of subject, time of day, and type of noise for those tasks that placed a heavy demand on short-term working memory, i.e., complex sorting (Noise x Sex, p < .05) and random letter generation (Sex x Noise x Time of Day, p < .05). The predicted effects for anagrams were not supported. These results call into question previous generalizations about the effects of noise on performance (Broadbent, 1978; Dornic, Sarnelid, Larson, Svensson, & Fernaeus, 1982; Poulton, 1977), alternative interpretations are presented.

Noise stress and circadian arousal in self-paced computation

Previous work(Frankenhaeuser & Lundberg, 1977) has shown that unpaced mental arithmetic is performed at slower rates in noise, despite unchanged catecholamine indices of arousal; only male subjects were used, tested early in the day. Since the times of testing entail arousal effects that interact with noise stress, and the sex of subject further modifies these interactions, a new experiment was designed to include these variables. Men and women were tested on the Norinder mental arithmetic task, in quiet or in noise, either in the morning, when arousal was low, or during the early evening, when temperature curves indicate that arousal should be high. Analysis of the number of problems attempted shows a significant drop for men in noise in the morning, but an interaction due to reversal of the noise effect in the evening; there is no main effect of noise when womens scores are included. The results are compatible with interpretations combining motivation and cognition, and they demonstrate the importance of the experimental variables in explaining noise stress effects.