Perceptual Discrimination Training: A Novel Method for Reducing Fear Generalization and Related Processes in Youth and Adults

• Main Authors: Ginat-Frolich, Rivkah, גינת-פרוליך, רבקה
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2020
• Subjects: Adults; Anxiety disorders; Authorship; Behavior; Biology; Children & youth; Impact factors; Keyboards; Paradigms; Physiology; Risk assessment
• ISBN: 9798471199040

The mechanism of generalization allows for the rapid processing of novel stimuli on the basis of shared characteristics. Though typically adaptive, when generalization occurs in excess it may become pathological. Such is the case with fear overgeneralization, whereby fear is transferred onto a novel, safe stimulus on the basis of a previous association to a known, feared stimulus. Notably, fear overgeneralization is a key symptom of anxiety related disorders and can result in functional impairment, such as avoidance. Therefore, finding ways to reduce fear overgeneralization is clinically relevant. One of the ways that fear overgeneralization is thought to occur is through deficits in perceptual discrimination. To this end, a novel perceptual discrimination task was created, with an overall aim of improving perceptual discrimination ability and decreasing fear generalization. The task consists of predesignated geometric shape pairs, differing in either shape or size, and increasing in degree of difficulty. In each trial a target shape is presented, followed by a fixation cross. Thereafter two shapes are presented, and participants are asked to select the shape that differs from the target shape. A placebo task was created using the same geometric shapes, with the shapes appearing on either the left or right side of the screen. Participants are then asked to indicate which side of the screen the shapes appeared on. The current dissertation research consists of three studies that assessed the perceptual discrimination training. Study 1 was conducted with healthy adults (N = 70; Ginat-Frolich et al., 2017); Study 2 was conducted with typically-developing children (N = 73; Ginat-Frolich et al., 2019a); and Study 3 was conducted with adults with high spider fear (N = 50; GinatFrolich et al., 2019b). Study’s 1 and 2 began with a differential fear conditioning task, where two colored cartoon bells were established as safety and danger cues respectively. Thereafter, participants completed either the training or placebo task. Next, a discrimination assessment task was administered that consisted of novel geometric shape pairs. Participants were asked to identify if in each pair was identical or different. Last, participants completed a generalization test that consisted of bell morphs (generalization stimuli; GSs) ranging in perceptual similarity from the safety cue to the danger cue. Self-report and psychophysiological measures were collected. Of note, as less is known about fear generalization in children, in Study 2 an additional control group was included who proceeded directly from the fear conditioning task to the generalization test. In Study 3, after completing either the training or placebo task, participants completed the discrimination assessment task. Thereafter, a behavioral-approach task (BAT) was administered consisting of 5 stimuli, ranging from a paper spider to a live tarantula. Participants were asked to bring each stimulus as close to themselves as possible. Last, participants completed a threat/safety discrimination task using schematic morphs ranging from a flower to a spider (i.e., the flower-spider task), while self-reported risk ratings and skin conductance were measured. In addition, as both fear overgeneralization and behavioral avoidance are key characteristics of anxiety disorders, the findings are clinically relevant, and set the stage for future research examining the training in clinically anxious populations.