Position and Identity in Visual Information Processing

<p>Information that is presented visually can be described in terms of its identity and in terms of its position, and a distinction can be drawn between what an item is and where that item is. For example, a letter displayed on a screen has both an identity (its name) and a spatial position; the spatial position can be specified either absolutely (the upper right quadrant) or relatively (beside the "x" and above the "y"). There is an obvious and intimate relationship between the identity component and the position component, and it is this relationship, between the the processing of position information and the processing of identity information, that forms the subject of the present thesis. First, the relevant I literature is reviewed. The relationship between position and identity is examined in the context of two major research areas: iconic memory and short term visual memory. Second, the concept of dimensional separability is considered with reference to the appropriate literature. The purpose is to indicate a theoretical framework within which the issue of concern may be profitably addressed. The key idea to be developed is that position and identity are asymmetrically separable dimensions. A small group of studies that offer tentative support to this conceptualization will be discussed. Third, the results of eight related experiments are reported. These experiments involve the recognition of position and/or identity information in a discrete trials procedure. The eight experiments fall into three separate groups. Experiments 1 to 3 examine the recognition of either position or identity information, with the two types of information presented in relative isolation. Several stimulus factors are manipulated in order to demonstrate differential effects upon the two dimensions. Experiments 4 to 6 examine the effect of the irrelevant dimension upon recognition of the relevant dimension. Experiment 4 uses a logically balanced set of stimuli, so that the irrelevant dimension is either consistent or inconsistent, whereas in Experiments 5 and 6 each dimension is examined in the context of consistent, inconsistent, or neutral information on the irrelevant dimension. Experiments 7 and 8 explore the integration of position and identity information by varying the task requirements. Shared attention conditions are contrasted with selective attention conditions to show the impact of attentional strategy. The thesis concludes with a general discussion of the results, and their accordance with the hypothesis of asymmetric separability.</p>

Position and Identity in Visual Information Processing

<p>Information that is presented visually can be described in terms of its identity and in terms of its position, and a distinction can be drawn between what an item is and where that item is. For example, a letter displayed on a screen has both an identity (its name) and a spatial position; the spatial position can be specified either absolutely (the upper right quadrant) or relatively (beside the "x" and above the "y"). There is an obvious and intimate relationship between the identity component and the position component, and it is this relationship, between the the processing of position information and the processing of identity information, that forms the subject of the present thesis. First, the relevant I literature is reviewed. The relationship between position and identity is examined in the context of two major research areas: iconic memory and short term visual memory. Second, the concept of dimensional separability is considered with reference to the appropriate literature. The purpose is to indicate a theoretical framework within which the issue of concern may be profitably addressed. The key idea to be developed is that position and identity are asymmetrically separable dimensions. A small group of studies that offer tentative support to this conceptualization will be discussed. Third, the results of eight related experiments are reported. These experiments involve the recognition of position and/or identity information in a discrete trials procedure. The eight experiments fall into three separate groups. Experiments 1 to 3 examine the recognition of either position or identity information, with the two types of information presented in relative isolation. Several stimulus factors are manipulated in order to demonstrate differential effects upon the two dimensions. Experiments 4 to 6 examine the effect of the irrelevant dimension upon recognition of the relevant dimension. Experiment 4 uses a logically balanced set of stimuli, so that the irrelevant dimension is either consistent or inconsistent, whereas in Experiments 5 and 6 each dimension is examined in the context of consistent, inconsistent, or neutral information on the irrelevant dimension. Experiments 7 and 8 explore the integration of position and identity information by varying the task requirements. Shared attention conditions are contrasted with selective attention conditions to show the impact of attentional strategy. The thesis concludes with a general discussion of the results, and their accordance with the hypothesis of asymmetric separability.</p>

Strongly masked content retained in memory made accessible through repetition

A growing body of evidence indicates that information can be stored even in the absence of conscious awareness. Despite these findings, unconscious memory is still poorly understood with limited evidence for unconscious iconic memory storage. Here we show that strongly masked visual data can be stored and accumulate to elicit clear perception. We used a repetition method across a wide range of conditions (Experiment 1) and a more focused follow-up experiment with enhanced masking conditions (Experiment 2). Information was stored despite being masked, demonstrating that masking did not erase or overwrite memory traces but limited perception. We examined the temporal properties and found that stored information followed a gradual but rapid decay. Extraction of meaningful information was severely impaired after 300 ms, and most data was lost after 700 ms. Our findings are congruent with theories of consciousness that are based on an integration of subliminal information and support theoretical predictions based on the global workspace theory of consciousness, especially the existence of an implicit iconic memory buffer store.

Masking interferes with haptic texture perception from sequential exploratory movements

Haptic texture perception is based on sensory information sequentially gathered during several lateral movements (“strokes”). In this process, sensory information of earlier strokes must be preserved in a memory system. We investigated whether this system may be a haptic sensory memory. In the first experiment, participants performed three strokes across each of two textures in a frequency discrimination task. Between the strokes over the first texture, participants explored an intermediate area, which presented either a mask (high-energy tactile pattern) or minimal stimulation (low-energy smooth surface). Perceptual precision was significantly lower with the mask compared with a three-strokes control condition without an intermediate area, approaching performance in a one-stroke-control condition. In contrast, precision in the minimal stimulation condition was significantly better than in the one-stroke control condition and similar to the three-strokes control condition. In a second experiment, we varied the number of strokes across the first stimulus (one, three, five, or seven strokes) and either presented no masking or repeated masking after each stroke. Again, masking between the strokes decreased perceptual precision relative to the control conditions without masking. Precision effects of masking over different numbers of strokes were fit by a proven model on haptic serial integration (Lezkan & Drewing, Attention, Perception, & Psychophysics 80(1): 177–192, 2018b) that modeled masking by repeated disturbances in the ongoing integration. Taken together, results suggest that masking impedes the processes of haptic information preservation and integration. We conclude that a haptic sensory memory, which is comparable to iconic memory in vision, is used for integrating sequentially gathered sensory information.

Revisiting the prioritization of emotional information in iconic memory

In this replication study, the previously reported prioritization of emotional stimuli in iconic memory (Kuhbandner et al . 2011. Psychol. Sci. 22 , 695–700. (doi:10.1177/0956797611406445)) was reinvestigated. Therefore, recall from iconic memory was measured for sets of visual images that were briefly presented in the periphery of the visual field. Using a partial-report technique, a central arrow presented at varying delays after the images was pointing to the location of the to-be-recalled target. In the direct replication (experiment 1, n = 41), participants were asked to verbally report the cued image (note that the entire planned sample size could not be reached owing to the COVID-19 pandemic), and in an extension experiment (experiment 2, n = 55), iconic memory was tested using a visual recognition test. Both experiments demonstrated prioritized selection of emotional targets from iconic memory, with higher verbal recall and visual recognition accuracy for negative and positive targets compared to neutral targets. In addition, we found that the presence of emotional distractors in the set interfered with the selection of neutral targets, thus confirming a trend that was observed in the original study. Exponential decay curves further revealed that both target and distractor valence primarily affected initial availability (in case of verbal recall) and attentional selection, whereas the decay of iconic memory with increasing cue delay was less sensitive to the emotional meaning.