Accurate identification but no priming and chance recognition memory for pictures in RSVP sequences

In 1969, Potter and Levy reported that recognition memory of accurately perceived RSVP pictures was extremely low, an effect that they attributed to disruption of memory consolidation. Here we report that the repetition of an RSVP picture (72-126 msec/picture) up to 31 times prior to when it became a target had no effect on identification accuracy. At these rates, forced-choice recognition memory was at chance. Single presentations of the pictures outside of the RSVP sequences readily resulted in substantial priming of their identification within the sequences. We offer a neural interpretation of Potter and Levy's explanation, as well as contemporary two-stage accounts of RSVP memory and attentional phenomena, based on the recent finding (Tovee & Rolls, 1995) that most of the information in inferior temporal cells is conveyed in the first 50msec of firing but the cells continue their activity for an additional 350msec. The additional activity, by our account, is required for memory and it is this activity that may be disrupted by attention to the next image during RSVP presentations. The critical factor for priming, if not memory in general, may be attention to the stimulus for a few hundred milliseconds beyond that required for its identification. Single-trial presentations thus manifest robust memory and priming effects - even when the stimulus cannot be identified - whereas RSVP conditions in which the stimulus can be identified result in poor memory.     

Memory load and latency in recognition of pictures

Color photographs of common scenes were used as memory and test items in two memory search experiments. Memory load varied from 2 to 24 items in one experiment and from 4 to 64 in the other. Latency of classification of test items increased with memory load. The increase is verb’ close to linear for loads up to six items, but for the full range of memory loads, it is negatively accelerated and approximately logarithmic. Sternberg’s (1966, 1969) serial theory of memory search, which predicts linear functions, holds for small memory loads of pictures. If serial search takes place for large memory loads, the speed of search must be faster than for small loads. It is also possible that items in memory loads of all sizes are accessed by a single process that generates a negatively accelerated relation between size of load and latency.     

Perceptual representations in false recognition and priming of pictures

Using a new procedure, we investigate whether imagination can induce false memory by creating a perceptual representation. Participants studied pictures and words with and without an imagery task and at test performed both a direct recognition test and an indirect perceptual identification test on pictorial stimuli. Corrected false recognition rates were 7% for pictures studied in word form (Experiment 1), 26% for pictures imagined once (Experiment 2), and 48% for pictures imagined multiple times (Experiment 3), although on the indirect test, no priming was found for these items. Furthermore, a perceptual/conceptual imagery manipulation did not affect the tendency to claim that imagined items had been studied as pictures (Experiment 4). These results suggest that the false memories reported on direct tests are not driven by perceptual representations.     

Perceptual processes in matching and recognition of complex pictures

The role of perceptual feature sampling in speeded matching and recognition was explored in 4 experiments. Experiments 1-3 involved a perceptual matching task with pictures of various objects and scenes. In Experiments 2 and 3, same-different judgments were given under time pressure. The main objective of the matching task was to obtain measures of the perceptual processing rates of different object features. Experiment 4 was an old-new recognition experiment, in which the same stimuli as those in the matching task were used. Response signals were used to limit processing time in the recognition task. The results demonstrated that it is possible to predict speeded recognition performance from performance in perceptual matching. A simple stochastic feature-sampling model provides a unified account of the data from the 4 experiments.     

A developmental study of recognition of pictures and nouns

Children at four age levels (4, 6, 8, and 10 years) were given continuous recognition tasks using concrete noun, abstract noun, and pictorial stimuli in a 4 × 3 factorial design. Pictures were recognized significantly better than concrete and abstract nouns at the 4- and 6-year age levels and significantly better than abstract nouns at the 8- and 10-year age levels. This supported Paivio's contention that pictures are easier to remember than words because of a greater possibility of dual encoding, while Rohwer's contention that there is a shift in recognition memory development received no support. There were no significant differences between recognition of concrete and abstract nouns at any age level, which opposed the findings from adult studies and suggested that Paivio's theoretical orientation would have to be extended in order to account for developmental data. Recognition for both concrete and abstract nouns was found to be linear and increasing significantly with age, but no age trends for picture recognition were found.     

Evidence for perceptual learning in pigeons' recognition memory for pictures

In two experiments, pigeons were trained on a recognition memory task, which required them to refrain from responding to a picture seen earlier that day. They learned this discrimination without detectable reliance on cues relating to the sequence of positive and negative trials. In both experiments, performance was significantly better when the same restricted set of stimuli was used each day than when an entirely novel set of stimuli was used each day, and in the former case there was less evidence of any significant decline in performance with increases in the interval between first and second presentations of a stimulus. The results suggest a powerful perceptual learning effect.     

Pictorial experience as a factor in the recognition of incomplete pictures

The study investigated the effects of distinctive feature emphasis and familiarity with pictorial materials on the recognition of incomplete pictures of common objects in three cultural groups. Contrary to a familiarity hypothesis Kxoe Bushman pre-school children were superior to both Zulu and white English-speaking Sth African pre-school children in recognizing fragmented pictures. Cultural differences were interpreted in terms of response strategies mediated by ecological and social variables. Children in each cultural group made effective use of distinctive features to aid recognition of fragmented pictures. The implications of these findings for the development of teaching materials were examined.     

Visual recognition memory for binary pictures: another look

Recognition memory for matrices of 0s and 1s was examined as a function of the number of elements (complexity) and density of those elements within the matrix. It was found that with greater density and lesser complexity, recognition performance improved. This result contradicts an earlier finding of Green and Purohit, who concluded that the more complicated matrices led to better performance. The present study suggests that their conclusion was erroneous and stemmed from failure to control the physical parameters of density and number of elements in the matrix. Implications for the general problem of recognition memory and eye movements are discussed.     

Enhanced memory for negatively emotionally charged pictures without selective rumination

Emotionally charged materials have been found to elicit higher levels of recall in many studies. However, the use of slow presentations and/or uncontrolled retention intervals may have allowed subjects to rehearse emotional materials preferentially. The authors presented a series of 5 pictures (1 emotionally charged) at a rate of 4 pictures per second, precluding selective rehearsal. In Experiment 1, subjects recalled the pictures immediately or after performing an arithmetic task for 20 s. In Experiment 2, the pictures were described as to-be-ignored distractors, and the memory test was unexpected. Stimulus emotionality greatly enhanced recall in all conditions. The speed of the presentations and the fact that enhancement did not spread to temporally adjacent items argues against some widely discussed mechanisms for emotional enhancement.     

The word-frequency paradox for recall/recognition occurs for pictures

A yes-no recognition task and two recall tasks were conducted using pictures of high and low familiarity ratings. Picture familiarity had analogous effects to word frequency, and replicated the word-frequency paradox in recall and recognition. Low-familiarity pictures were more recognizable than high-familiarity pictures, pure lists of high-familiarity pictures were more recallable than pure lists of low-familiarity pictures, and there was no effect of familiarity for mixed lists. These results are consistent with the predictions of the Search of Associative Memory (SAM) model.     

Visual recognition memory for large and small binary pictures.

Recognition memory for pictures was tested using matrices of 0s and 1s as stimuli in two experiments. In the first experiment dimensionality of matrices was varied (5 X 5 and 10 X 10 matrices). The results showed better recognition memory for 10 X 10 matrices. The second experiment investigated the importance of certain areas, such as center or surround, using 10 X 10 matrices only. The results suggested that neither center nor surround is given unusual weight.     

Visual mediation and the haptic recognition of two-dimensional pictures of common objects

A set of three experiments was performed to investigate the role of visual imaging in the haptic recognition of raised-line depictions of common objects. Blindfolded, sighted (Experiment 1) observers performed the task very poorly, while several findings converged to indicate that a visual translation process was adopted. These included (1) strong correlation between image-ability ratings (obtained in Experiment 1 and, independently, in Experiment 2) and both recognition speed and accuracy, (2) superior performance with, and greater ease of imaging, two-dimensional as opposed to three-dimensional depictions, despite equivalence in rated line complexity, and (3) a significant correlation between the general ability of the observer to image and obtained imageability ratings of the stimulus depictions. That congenitally blind observers performed the same task even more poorly, while their performance did not differ for two- versus three-dimensional depictions (Experiment 3), provides further evidence that visual translation was used by the sighted. Such limited performance is contrasted with the considerable skill with which real common objects are processed and recognized haptically. The reasons for the general difference in the haptic performance of two- versus three-dimensional tasks are considered. Implications for the presentation of spatial information in the form of tangible graphics displays for the blind are also discussed.     

Long-term perceptual specificity effects in recognition memory: the transformed pictures paradigm.

The effects of a study/test mismatch in the viewing mode of natural scenes on recognition memory performance were examined. At both encoding and retrieval, scenes were presented either by being divided into quarters that were displayed in a sequential cumulative fashion or by scrolling the images through the screen, thereby gradually revealing the content of the images. Half of the participants were tested immediately after encoding and the other half after 48 hours. For both the immediate and delayed retrieval conditions, better recognition memory was demonstrated when viewing modes matched across study and test than when they mismatched. Implications for current processing and multiple systems views of memory are discussed.     

Retention interval modulates the effect of negative arousing pictures on recognition memory

This study examined the modulation of retention interval in the effect of emotion as elicited from negative and positive arousing pictures on recognition memory. Participants underwent seven encoding sessions and one testing session. The encoding sessions were separated by certain lengths of intervals such that there were seven levels of time gaps between encoding and testing. In each encoding session, participants learned a list of 30 pictures (including 10 neutral, 10 positive and 10 negative pictures). In the testing session, they were presented with a list of 210 old and 210 new pictures and made “old/new” and “remember/know” judgements. The results showed that negative arousing pictures enhanced overall recognition in the 2-week interval and enhanced recollection in both the 2-week and 3-week intervals. However, neither negative nor positive arousing pictures had any effect on familiarity regardless of retention interval. The current study contributes to the literature by suggesting that longer retention intervals do not necessarily lead to more pronounced effects of negative arousing pictures and that the modulation of retention interval depends on the specific components of recognition memory.     

Visual-word recognition thresholds for screen-fragmented names of the Snodgrass and Vanderwart pictures

The set of names corresponding to the pictures from Snodgrass and Vanderwart (1980) were screen fragmented by means of a series of procedures implemented in Microsoft QuickBasic on a Macintosh microcomputer. Words were screen fragmented by deleting blocks of pixels from their images rather than by deleting individual letters. The screen-fragmentation procedure is particularly useful for the present set of words, in which a large proportion of the names of the pictures are short (fewer than five letters). The screen-fragmentation procedure can produce any number of fragmentation levels. In the present implementation, eight levels of fragmented images were produced, to correspond to the eight levels available for the Snodgrass and Vanderwart pictures.