Overgeneralization Of Fear Research Articles

Overgeneralization of Conditioned Fear in the Anxiety Disorders

According to many conditioning accounts of clinical anxiety, the central pathogen can be found in aberrant acquisition or extinction of learned fear to neutral stimuli (i.e., conditioned stimuli [CS]) paired with an aversive unconditioned stimulus (US). While overresponding to the CS is an important candidate source of anxiety pathology, both clinical observation and mounting experimental data implicate generalization of fear to stimuli resembling the CS as an equally promising candidate (e.g., Grillon & Morgan, 1999; Lissek et al., 2005; Lissek et al., 2010; Mineka & Zinbarg, 1996). Important to the current issue on ‘‘Trauma and Memory,’’ generalization of fear to stimuli resembling those present during a traumatic event is a core feature of the posttraumatic stress response (American Psychiatric Association, 2000) and is likely influenced by conditioning-dependent modifications to the neural representation of the CS stored in memory. The current paper (1) summarizes the connection between conditioned-fear generalization and pathologic anxiety including a recent empirical example demonstrating the link and (2) explores memorial substrates of conditioned generalization and the ways they are related to overgeneralization of the kind seen in anxiety pathology.

P01-138 - Impaired discriminative fear learning in panic disorder

ObjectivesFear conditioning (FC) has been proposed as crucial factor in the etiology and maintenance of panic disorder (PD). This study compared the acquisition of discriminative fear learning between PD patients and healthy subjects (CTR). The main purpose was to test the hypothesis that abnormalities in this process may exist in this population, particularly referred to conditioned responses (CRs) and discriminative fear learning acquisition.MethodsAversive discriminative conditioning paradigm was administered to 45 patients with a DSM-IV diagnosis of PD with agoraphobia and to 43 healthy subjects. The visual-auditory conditioning paradigm is composed by four visual stimuli as conditioned stimulus (CSs) and a startlingly loud sound as the unconditioned stimulus (US). Only one stimulus (CS+) was followed by the US, instead remainder stimuli were never paired with the US (CS-). The protocol consisted of 3 phases: habituation (HAB), acquisition (ACQ) and extinction (EXT). Skin conductance response (SCR) was used as dependent variable.ResultsDuring HAB phase no differences were found in response to all stimuli. During ACQ phase, the two groups did not differ in response to CS+; instead patients showed significantly greater reactivity to CS- than controls.ConclusionResults suggest equal level of fear acquisition and impaired discriminative fear learning in PD population; moreover discriminative deficit is driven by enhanced safety learning rather than any abnormality in excitatory danger learning. Enhanced responding to CS- among PD may also be interpreted as over-generalization of conditioned fear. Our result have important clinical implication, particularly for behaviour cognitive therapy in Panic Disorder.

Overgeneralization of Conditioned Fear as a Pathogenic Marker of Panic Disorder

Classical conditioning features prominently in many etiological accounts of panic disorder. According to such accounts, neutral conditioned stimuli present during panic attacks acquire panicogenic properties. Conditioned stimuli triggering panic symptoms are not limited to the original conditioned stimuli but are thought to generalize to stimuli resembling those co-occurring with panic, resulting in the proliferation of panic cues. The authors conducted a laboratory-based assessment of this potential correlate of panic disorder by testing the degree to which panic patients and healthy subjects manifest generalization of conditioned fear. Nineteen patients with a DSM-IV-TR diagnosis of panic disorder and 19 healthy comparison subjects were recruited for the study. The fear-generalization paradigm consisted of 10 rings of graded size presented on a computer monitor; one extreme size was a conditioned danger cue, the other extreme a conditioned safety cue, and the eight rings of intermediary size created a continuum of similarity from one extreme to the other. Generalization was assessed by conditioned fear potentiating of the startle blink reflex as measured with electromyography (EMG). Panic patients displayed stronger conditioned generalization than comparison subjects, as reflected by startle EMG. Conditioned fear in panic patients generalized to rings with up to three units of dissimilarity to the conditioned danger cue, whereas generalization in comparison subjects was restricted to rings with only one unit of dissimilarity. The findings demonstrate a marked proclivity toward fear overgeneralization in panic disorder and provide a methodology for laboratory-based investigations of this central, yet understudied, conditioning correlate of panic. Given the putative molecular basis of fear conditioning, these results may have implications for novel treatments and prevention in panic disorder.