Disruptive effects of prior information on tachistoscopic recognition

Smith, Haviland, Reder, Brownell, and Adams (1976) found tachistoscopic letter recognition to be disrupted by advance information about possible letter alternatives. An association of “before-disruption” with a bias to respond “same” in same-different judgment led Smith et al. to conclude that incidental mask features corresponding to a precued letter were erroneously incorporated into the target letter decision. Experiments 1 and 2 in the present study failed to replicate the before-disruption effect under conditions similar to those of Smith et al., although precuing produced a strong bias to respond “same.” Similarity between “same” and “different” alternatives was manipulated in Experiment 3 by selecting letter pairs differing in one critical feature (P-R, O-Q, C-G, F-E) for one group of subjects, and re-pairing the same letters (P-G, O-E, C-R, F-Q) for another group. Contrary to Smith et el., precuing interacted significantly with pair similarity, such that before-disruption occurred only with similar alternatives. In contrast, precuing produced equivalent “same-bias” in both groups. The dependence of before-disruption on pair similarity was extended to two-alternative forced-choice recognition in Experiment 4. Together with inconsistencies in the Smith et al. data and more detailed analysis of present recognition errors, the results suggest (1) the before-disruption and same-bias effects of precuing are mediated by separate mechanisms, and (2) before-disruption reflects loss of target letter information rather than direct incorporation of extraneous mask features.     

Order of report and processing in tachistoscopic recognition

Two groups of 12 Ss were shown tachistoscopically 4 letters and 4 numbers. Within these alpha-numeric sequences, three variables were systematically manipulated: grouping of items, initial item, and familiarity of the letter sequences. One group of Ss reported first letters then numbers from each sequence; the other group reported numbers then letters. The results indicated that grouping, redundancy, and order of report had significant effects on letter accuracy but not on number accuracy. These effects were interpreted in terms of processing, particularly the use of spatial and identity information during recognition.     

Buffer storage modality and identification time in tachistoscopic recognition

According to Sperling's (1967) model of short-term memory briefly presented masked stimuli are rapidly read into a non-visual Recognition Buffer (the RB model). An alternative interpretation of the data is that the stimulus information is coded into a non-iconic Visual Buffer where it is held while a much slower recognition process takes place (the VB model). The high frequency of errors in experiments with sequentially presented stimuli appears to refute the possibility that recognition is as rapid as suggested by the RB model. However these data may be attributed to variations in effective stimulus duration and stimulus quality rather than to slow recognition time. In an experiment to control for these effects, normal, laterally inverted and spaced digits were presented in a rapid sequence (1-10 items/s) with intervening pattern masks to keep the stimulus/mask interval constant. The recall data showed that order errors increased with rate of presentation but that item errors remained invariant. At the fastest rates of presentation there were fewer order errors for spaced than for coincident digits. It was argued that the results, as a whole, were more consistent with the VB than the RB model and that there is no evidence for identification times as fast as 10-40 ms/item.     

Lateral differences in tachistoscopic recognition of bilaterally presented verbal material.

When subjects have to report verbal material presented tachistoscopically simultaneously on both sides of a fixation point, right visual field superiority has been obtained in several experiments using a central task technique, i.e. where a stimulus presented at the fixation point had to be identified before reporting the rest of the material. Without a central task, left visual field superiority has generally been obtained. It has been suggested to attribute the difference to control of eye fixation by the central task. An alternative interpretation, that the central task modifies the order of attentional scanning was put to the test in Experiment I. With two normally printed words, right visual field superiority was obtained with a central task and left visual field superiority without it. It was predicted that with mirrored words, the opposite pattern would be obtained, yet here right visual field superiority was obtained both without and with a central task. Experiment II shows that the latter result is nevertheless dependent on scanning order, for it can be completely inverted through recall order instructions. It is concluded that lateral differences observed with bilateral presentation cannot be explained without taking account of optional processing priorities, but that the factors on which the latter depend are not yet fully understood.     

Information processing during face recognition: the effects of familiarity, inversion, and morphing on scanning fixations

Where we make ocular fixations when viewing an object likely reflects interactions between 'external' object properties and internal 'top-down' factors, as our perceptual system tests hypotheses and attempts to make decisions about our environment. These scanning fixation patterns can tell us how and where the visual system gathers information critical to specific tasks. We determined the effects of the internal factors of expertise, experience, and ambiguity on scanning during a face-recognition task, in eight subjects. To assess the effects of expertise, we compared upright with inverted faces, since it is hypothesized that inverted faces do not access an orientation-dependent face-expert processor. To assess the effects of experience, we compared famous with novel faces, as famous faces would have stronger internal representations than anonymous ones. Ambiguity in matching seen and remembered faces was manipulated with morphed faces. We measured three classes of variables: (i) total scanning time and fixations; (ii) the spatial distribution of scanning; and (iii) the sequence of scanning, using first-order Markov matrices for local scan structure and string editing for global scan structure. We found that, with inverted faces, subjects redistributed fixations to the mouth and lower face, and their local and global scan structure became more random. With novel or morphed faces, they scanned the eyes and upper face more. Local scan structure was not affected by familiarity, but global scan structure was least random (most stereotyped) for novel upright faces. We conclude that expertise (upright faces) leads to less lower-face scanning and more predictable global patterns of information gathering. Experience (famous faces) leads to less upper-face scanning and more idiosyncratic global scan structures, suggesting a superseding influence of facial memories. With morphed faces, subjects return to the upper face to resolve ambiguity, implying a greater importance of this region in face recognition.     

Effects of familiarity level and repetition on recognition accuracy

Theories of recognition memory based on signal detection theory posit that a recognition decision is similar to a psychophysical judgment. Like a judgment of stimulus brightness or loudness, a recognition judgment is based on the value of a unidimensional signal computed for the test item. This signal has been called the strength or familiarity value. One prediction of these models is that the ability to discriminate between a studied and nonstudied test item depends on the ability to detect the difference in their familiarities. This ability in turn is influenced by the items' familiarity levels; discrimination should become more difficult as the familiarity of both items increases. This prediction was supported in 3 experiments using a forced-choice procedure. Also, accuracy was higher when the list contained repeated items rather than a comparable number of distinct items.     

Novelty effects on recollection and familiarity in recognition memory

Recognition memory is better for novel or distinctive items than for non-novel items. However, it is not known whether these effects reflect changes in recollection or in familiarity-based recognition judgments. Some previous results have indicated that recollection should be more sensitive to novelty than to familiarity, whereas other results have suggested the opposite. We used avon Restorff paradigm in which a small proportion of studied items were made novel by presenting them in a color different from that of the majority of the study items. Memory was tested using a remember-know procedure. Across two experiments, stimulus novelty was found to benefit both recollection and familiarity. The effects on familiarity were observed under intentional and incidental encoding conditions, whereas the effects on recollection were significantly reduced, and no longer significant, under incidental as compared with intentional encoding conditions. Thus, both processes benefit from stimulus novelty, but the extent to which recollection benefits from novelty depends on the encoding condition.