Identifying objects from a haptic glance

Subjects identified common objects under conditions of a “haptic glance,” a brief haptic exposure that placed severe spatial and temporal constraints on stimulus processing. They received no advance cue, a superordinate-level name as cue, or a superordinate and basic-level name as cue. The objects varied in size relative to the fingertip and in the most diagnostic attribute, either texture or shape. The data suggest that object recognition can occur when global volumetric primitives cannot directly be extracted. Even with no cue, confusion errors resembled the target object and indicated extraction of material and local shape information, which was sufficient to provide accuracy above 20%. Performance improved with cuing, and the effect of exposure duration was observed primarily with minimal cuing, indicating compensatory effects of top-down processing.     

Short-term memory for flavour

The short-term memory for the flavour of a wine in frequent but nonexpert drinkers was studied in an experiment comparing memory for wine under conditions where participants imagined and remembered a target wine with memory under conditions where participants carried out subsequent imaging and image rating tasks on the wine and on competing mental images. The results show that the cognitive operation of mental image rating produced enhanced memory when the operations were performed on the image of the target wine and somewhat impaired memory when operations were performed on an image of a competing flavour or operations performed on mental images in other domains. It is concluded that sensory traces of flavour may be effectively maintained in short-term memory when supported by appropriate encoding operations.     

Short-term memory for time intervals

The effect of intertrial interval, preset interval, and retention interval on the performance of rats in a time estimation task was described. On each trial a signal was presented for a duration of 2 to 8 sec. Eighteen rats were trained to press one lever (the short response) if the signal was shorter than 4 sec, and another lever (the long response) if the signal was longer than 4 sec. When trials were massed (Experiment 1), the percentage long response was affected by the classification of the previous signal, but not by its actual duration. This suggests that the animals remembered the response made on the previous trial, but not the signal duration. If a response was not permitted on the previous trial (Experiment 2), the duration or classification of the previous signal had no effect on performance. This supports the conclusion from the first experiment and suggests that an animal can reset its internal clock in less than 2 sec. In Experiment 3, the difference limen of the psychophysical function increased with the duration of the retention interval, but the point of subjective equality did not change. This suggests that resetting of the internal clock occurs on a non-time dimension.     

Short-term memory for intonation.

Ss were presented with lists of 16 words, each word spoken in one of four intonations. The final word was a repetition of one of the first 15 words, 40 Ss having to judge whether it was spoken in the same intonation as its earlier occurrence. A control group of 40 Ss did a similar task, ignoring intonation. Retention of intonation was significantly poorer, indicating that intonation is an additional load not normally retained. This argues against acoustic or articulatory encoding in short-term memory and in favor of an abstract-verbal encoding mode. Results are also interpreted as supporting the position that verbal and motor short-term membory obey similar laws.     

Working memory for relations among objects

Across many areas of study in cognition, the capacity of working memory (WM) is widely agreed to be roughly three to five items: three to five objects (i.e., bound collections of object features) in the literature on visual WM or three to five role bindings (i.e., objects in specific relational roles) in the literature on memory and reasoning. Three experiments investigated the capacity of observers’ WM for the spatial relations among objects in a visual display, and the results suggest that the “items” in WM are neither simply objects nor simply role bindings. The results of Experiment 1 are most consistent with a model that treats an “item” in visual WM as an object, along with the roles of all its relations to one other object. Experiment 2 compared observers’ WM for object size with their memory for relative size and provided evidence that observers compute and store objects’ relations per se (rather than just absolute size) in WM. Experiment 3 tested and confirmed several more nuanced predictions of the model supported by Experiment 1. Together, these findings suggest that objects are stored in visual WM in pairs (along with all the relations between the objects in a pair) and that, from the perspective of WM, a given object in one pair is not the same “item” as that same object in a different pair.     

Orientation-specific possibility priming for novel three-dimensional objects

Priming effects on the object possibility task, in which participants decide whether line drawings could or could not be possible three-dimensional objects, may be supported by the same processes and representations used in recognizing and identifying objects. Three experiments manipulating objects’ picture-plane orientation provided limited support for this hypothesis. Like old/new recognition performance, possibility priming declined as study-test orientation differences increased from 0° to 60°. However, while significant possibility priming was not observed for larger orientation differences, recognition performance continued to decline following 60°–180° orientation shifts. These results suggest that possibility priming and old/new recognition may rely on common viewpoint-specific representations but that access to these representations in the possibility test occurs only when study and test views are sufficiently similar (i.e., rotated less than 60°).     

Short-term memory models for choice behavior

In this paper we consider the effect of imposing memory restrictions on the accumulator and random-walk models of choice behavior outlined by Audley (Psychological Review, 1960, 67, 1–15). Specifically, it is assumed that subjects apply criteria to the numbers of impulses received, and that if the criteria are not satisfied by the time w impulses have been received, then thereafter the criteria are only applied to w impulses, which could, for example, be the last w impulses received. Exact and approximate mathematical approaches and simulation techniques are presented in detail. The results obtained demonstrate that both the restricted accumulator and the restricted random-walk models can make qualitative predictions in line with much recent data.     

Reduction of false recognition through haptic presentation of objects

False recognition of an item that is not presented (the lure) can occur when participants study and are tested on their recognition of items related to the lure. False recognition is reduced when the study and test modalities are congruent (e.g., both visual) rather than different (e.g., visual study and auditory test). The present study examined whether such a congruency effect occurs for haptic and auditory modalities. After studying items presented haptically or auditorily, participants took a haptic or auditory recognition test. False recognition was reduced when both the study and test were haptic, but not when the study was auditory and the test was haptic. These results indicate that cues encoded through the haptic modality can reduce false recognition.     

Generating complex three-dimensional stimuli (Greebles) for haptic expertise training

An apparatus is described that accurately measures response times and video records hand movements during haptic object recognition using complex three-dimensional (3-D) forms. The apparatus was used for training participants to become expert at perceptual judgments of 3-D objects (Greebles) using only their sense of touch. Inspiration came from previous visual experiments, and therefore training and testing protocols that were similar to the earlier visual procedures were used. Two sets of Greebles were created. One set (clay Greebles) was hand crafted from clay, and the other (plastic Greebles) was machine created using rapid prototyping technology. Differences between these object creation techniques and their impact on perceptual expertise training are discussed. The full set of these stimuli may be downloaded from www.psychonomic.org/archive/.     

Short-term storage capacity for visual objects depends on expertise

Visual short-term memory (VSTM) has traditionally been thought to have a very limited capacity of around 3-4 objects. However, recently several researchers have argued that VSTM may be limited in the amount of information retained rather than by a specific number of objects. Here we present a study of the effect of long-term practice on VSTM capacity. We investigated four age groups ranging from pre-school children to adults and measured the change in VSTM capacity for letters and pictures. We found a clear increase in VSTM capacity for letters with age but not for pictures. Our results indicate that VSTM capacity is dependent on the level of expertise for specific types of stimuli.     

Explicit and implicit memory for rotating objects

Although both the object and the observer often move in natural environments, the effect of motion on visual object recognition ha not been well documented. The authors examined the effect of a reversal in the direction of rotation on both explicit and implicit memory for novel, 3-dimensional objects. Participants viewed a series of continuously rotating objects and later made either an old-new recognition judgment or a symmetric-asymmetric decision. For both tasks, memory for rotating objects was impaired when the direction of rotation was reversed at test. These results demonstrate that dynamic information can play a role in visual object recognition and suggest that object representations can encode spatiotemporal information.     

Incidental visual memory for objects in scenes

Three experiments were conducted to investigate the existence of incidentally acquired, long-term, detailed visual memory for objects embedded in previously viewed scenes. Participants performed intentional memorization and incidental visual search learning tasks while viewing photographs of real-world scenes. A visual memory test for previously viewed objects from these scenes then followed. Participants were not aware that they would be tested on the scenes following incidental learning in the visual search task. In two types of memory tests for visually specific object information (token discrimination and mirror-image discrimination), performance following both the memorization and visual search conditions was reliably above chance. These results indicate that recent demonstrations of good visual memory during scene viewing are not due to intentional scene memorization. Instead, long-term visual representations are incidentally generated as a natural product of scene perception.     

On haptic and motor incorporation of tools and other objects

This article presents a conceptual discussion on the phenomenon of incorporation of tools and other objects in the light of Maine de Biran’s philosophy of the relation between the body and the motor will. Drawing on Maine de Biran’s view of the body as that portion of the material world which directly obeys one’s motor will, as well as on his view (supported by studies in contemporary cognitive science) of active touch as the perceptual modality that is sensitive to objects as fields of forces resisting the perceiver’s movements, we discuss the phenomena of motor incorporation and haptic incorporation, as well as the relation between them. Motor incorporation occurs when something is integrated into the motor system, i.e. when practice enables one to animate an object as directly, effortlessly and fluently as one is able to animate one’s own body. The subject then has the experience of acting there, where the object is located, not at the body–object interface. In order to better understand the phenomenon of motor incorporation, we highlight the phenomenological difference between directly and indirectly moving something. Haptic incorporation occurs when something is integrated into the haptic system, i.e. when an object is used as an instrument for the haptic perception of other objects. Finally, we seek to shed light on the phenomenon of transparency, understanding the transparency acquired by the incorporated object as both a relational property and a matter of degrees.     

Orientation-specific possibility priming for novel three-dimensional objects.

Priming effects on the object possibility task, in which participants decide whether line drawings could or could not be possible three-dimensional objects, may be supported by the same processes and representations used in recognizing and identifying objects. Three experiments manipulating objects' picture-plane orientation provided limited support for this hypothesis. Like old/new recognition performance, possibility priming declined as study-test orientation differences increased from 0 degree to 60 degrees. However, while significant possibility priming was not observed for larger orientation differences, recognition performance continued to decline following 60 degrees-180 degrees orientation shifts. These results suggest that possibility priming and old/new recognition may rely on common viewpoint-specific representations but that access to these representations in the possibility test occurs only when study and test views are sufficiently similar (i.e., rotated less than 60 degrees).     

Children's haptic and cross-modal recognition with familiar and unfamiliar objects

Five-year-old children explored multidimensional objects either haptically or visually and then were tested for recognition with target and distractor items in either the same or the alternative modality. In Experiments 1 and 2, haptic, visual, and cross-modal recognition were all nearly with familiar objects; haptic and visual recognition were also excellent with unfamiliar objects, but cross-modal recognition was less accurate. In Experiment 3, cross-modal recognition was also less accurate than within-mode recognition with familiar objects that were members of the same basic-level category. The results indicate that children's haptic recognition is remarkably good, that cross-modal recognition is otherwise constrained, and that cross-modal recognition may be accomplished differently for familiar and unfamiliar objects.     

Short-term memory for repeated and non-repeated items

Digit sequences containing repeated items are retained differently in short-term memory from sequences containing no repeated items. The repeated items are remembered better or worse than items in the corresponding positions of “all-different” sequences depending on the number of times the item is repeated, the number of items repeated, the number of items intervening between the occurences of a repeated item, and the position of the repeated items in relation to the beginning and end of the sequence. In every type of repetition studied, except one, memory for the non-repeated items in sequences with repeated items is better than for the corresponding items of all-different sequences. This is true in some cases despite significant specific interference between the (non-repeated) items following the separated occurrences of repeated items. The negative effects in memory for repeated items and the positive effects in memory for non-repeated items are greater when the items are presented at the rate of five per sec. than at one per sec., contrary to the hypothesis that differential rehearsal is responsible for these effects. The results are interpreted as supporting an “associative,” as opposed to a “non-associative,” theory of short-term memory, as this distinction is defined in the paper.