Historical review of the concept of anhedonia

During the last decades, the term "anhedonia", conceptualized as a incapacity to experience pleasure, have become associated with conditions as different as schizophrenia and depression. This paper deals with the conceptual and historial frames in which anhedonia was first constructed, and shows that the sources for the current fuzziness of this concept include neglect of the fact that anhedonia is conceptually parasitical upon the notion of pleasure, that it has been rather superficially conceptualized as the reduction or abolition in a "putative" function which itself is unlikely to be unitary in nature, and that it has never been quite specified whether the mechanism concerns a deficit in brain signal or not.     

Evidence for a grammar-specific deficit in children

BACKGROUND: Specific language impairment (SLI) is a disorder in which language acquisition is impaired in an otherwise normally developing child. SLI affects around 7% of children. The existence of a purely grammatical form of SLI has become extremely controversial because it points to the existence and innateness of a putative grammatical subsystem in the brain. Some researchers dispute the existence of a purely grammatical form of SLI. They hypothesise that SLI in children is caused by deficits in auditory and/or general cognitive processing, or social factors. There are also claims that the cognitive abilities of people with SLI have not yet been sufficiently characterised to substantiate the existence of SLI in a pure grammatical form. RESULTS: We present a case study of a boy, known as AZ, with SLI. To investigate the claim for a primary grammatical impairment, we distinguish between grammatical abilities, non-grammatical language abilities and non-verbal cognitive abilities. We investigated AZ's abilities in each of these areas. AZ performed normally on auditory and cognitive tasks, yet exhibited severe grammatical impairments. This is evidence for a developmental grammatical deficit that cannot be explained as a by-product of retardation or auditory difficulties. CONCLUSIONS: The case of AZ provides evidence supporting the existence of a genetically determined, specialised mechanism that is necessary for the normal development of human language.     

Social and physical anhedonia and valence and arousal aspects of emotional experience.

Two studies examined whether self-reported anhedonia is associated with 2 facets of emotional experience, valence and arousal. In Study 1, in multiple assessments of emotional experience (e.g., naturalistic and lab contexts and social and nonsocial situations), people with elevated social anhedonia (n = 40) reported less intensity of positive affect than both controls (n = 30) and people with elevated perceptual aberration-magical ideation (n = 29). Social anhedonia was also associated with providing less emotional content when describing what it is like to experience positive situations. In contrast, both social anhedonia and perceptual aberration-magical ideation were associated with increased frequency of negative affect for their daily experiences. Moreover, social anhedonia was not associated with a decrease specifically in high-arousal emotions. In Study 2 (n = 339), social and physical anhedonia (but not perceptual aberration-magical ideation) were again associated with decreased self-reported positive affect to lab stimuli. In these studies, results were not statistically accounted for by personality, current mood, or current distress. Overall, results suggest anhedonia may be associated with a general decrease in self-reported positive affect intensity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a sensation-seeking scale.

This article reports the development of a Sensation Seeking Scale (SSS) designed to quantify the construct: "optimal stimulation level." Items were written, using the construct as a guide, and given to undergraduates. The items were factor analyzed. A general factor was found and the item-factor correlation pattern was similar in males and females. In another sample, satisfactory reliability for the SSS was obtained and it was found to be positively correlated with field independence as measured by the Embedded Figures Test. In a third sample, nonsignificant correlations between SSS and Howard's Stimulus Seeking Maze tests were found. A significant negative correlation between SSS and anxiety, as measured by the Multiple Affect Adjective Check List was obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for a central cholinergic deficit in congenital ornithine transcarbamylase deficiency

Congenital ornithine transcarbamylase (OTC) deficiency is the most common inborn error of urea cycle enzymes in humans. A large percentage of survivors of neonatal OTC deficiency suffer severe developmental disorders, including seizures, mental retardation and cerebral palsy. Neuropathological studies reveal ventricular enlargement, cerebral atrophy and delayed myelination, as well as Alzheimer type II astrocytosis. Using the sparse-fur (spf) mouse model of congenital OTC deficiency, studies of central cholinergic integrity revealed a developmental delay in choline acetyltransferase activity and of high-affinity [3H]-choline uptake in several brain structures. Subsequent studies of muscarinic cholinergic binding site distribution showed a widespread loss of M1 sites, consistent with cholinergic cell loss. These alterations are similar to those reported in Alzheimer's disease, suggesting that the severe cognitive dysfunction in congenital OTC deficiency may at least partly result from a muscarinic cholinergic lesion. Possible mechanisms involved in the pathogenesis of cholinergic cell loss in congenital OTC deficiency include ammonia-induced inhibition of pyruvate and alpha-oxoglutarate oxidation, resulting in decreased synthesis of acetyl CoA and a cerebral energy deficit, as well as NMDA receptor-mediated excitotoxicity. Treatment of spf mice with acetyl-L-carnitine (ALCAR) results in partial recovery of the developmental choline acetyltransferase deficit, suggesting a potential therapeutic benefit of ALCAR in congenital OTC deficiency. Other therapies currently used include ammonia-lowering strategies (using sodium benzoate or sodium phenylacetate) and, in severe cases, liver transplantation.     

Repetition blindness and aging: Evidence for a binding deficit involving a single, theoretically specified connection.

Tested 2 main hypotheses for explaining repetition blindness (RB), a difficulty in encoding and recalling rapidly presented repeated words in sentences. Under 1 hypothesis, RB reflects an inhibitory process and should be more pronounced in young than in older Ss, who typically exhibit diminished inhibitory processes. Under the 2nd hypothesis, RB reflects a failure to bind a specific connection: The 2nd connection from the single node for encoding a repeated word is difficult to form under time pressure. Under this binding hypothesis, young adults should exhibit less RB than older adults, who typically require more time to form new connections. Results supported a version of the binding hypothesis but contradicted the inhibition hypothesis, and did not support hypotheses whereby RB reflects either a refractory effect or perceptual fusion of the repeated words (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Belief and feeling: Evidence for an accessibility model of emotional self-report.

This review organizes a variety of phenomena related to emotional self-report. In doing so, the authors offer an accessibility model that specifies the types of factors that contribute to emotional self-reports under different reporting conditions. One important distinction is between emotion, which is episodic, experiential, and contextual, and beliefs about emotion, which are semantic, conceptual, and decontextualized. This distinction is important in understanding the discrepancies that often occur when people are asked to report on feelings they are currently experiencing versus those that they are not currently experiencing. The accessibility model provides an organizing framework for understanding self-reports of emotion and suggests some new directions for research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scales for physical and social anhedonia

Devised 2 true–false scales to measure anhedonia, the lowered ability to experience pleasure: a 40-item Physical Anhedonia (PA) scale and a 48-item Social Anhedonia (SA) scale. After scale development using 371 college students, the final version was given to 505 normal adults stratified by social class, age (18–45), and sex, and to 123 male schizophrenics. The potential artifacts of social desirability, acquiescence, and random responding were ruled out. Coefficient alpha values for PA and for SA were .74 and .85 for male normal Ss and .82 and .85 for male schizophrenics. Schizophrenics scored more anhedonic than normal Ss on both PA and SA. Schizophrenics' scores on PA fell into 2 clusters of scores, one resembling the total distribution of the normal Ss, and a 2nd cluster consisting of scores that were more anhedonic than those of the normal Ss. Anhedonics were more often poor premorbid and hedonics more often good premorbid. The PA scale may be useful for testing the hypotheses, advanced by several theorists, that anhedonia is genetically transmitted and that nonpsychotic anhedonics are at high risk for schizophrenia. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overextension of conjunctive concepts: Evidence for a unitary model of concept typicality and class inclusion.

Four experiments investigated how people judge both the typicality and membership of items in conjunctive concepts such as school furniture or sports which are games. Judgments of membership in conjunctions were overextended, and there was asymmetry between the constituent concepts in their influence on relative conjunctive concept membership. The results are discussed in the light of recent theoretical disputes about the modeling of concept representations and the process of forming conjunctions (Cohen & Murphy, 1984; Osherson & Smith, 1981, 1982; Smith & Osherson, 1984). A theory is proposed in which constituent intensions are combined to form a composite prototype for the conjunction. Membership in both single and conjunctive concepts is then determined in the same unitary fashion, by placing a membership criterion on the perceived similarity of possible exemplars to the prototype. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Normal development and psychopathological impairment of the concept of the object on the Rorschach.

Responses to the Rorschach were analyzed according to developmental principles of differentiation, articulation, and integration in a longitudinal study of normal development (37 Ss at ages 11-12, 13-14, 17-18, and 30) and in a sample of 48 adolescent and young adult inpatients. Normal development showed a significant increase in well-differentiated, highly articulated, and integrated human figures seen in constructive and reciprocal interactions. In comparison with normals, patients gave human figures that were significantly more inaccurately perceived, distorted, and partial and that were seen as inert or engaged in unmotivated, incongruent, nonspecific, and malevolent activity. Unexpectedly, however, patients, as compared with normals, gave significantly more human responses at developmentally lower levels on accurately perceived responses and at developmentally advanced levels on inaccurately perceived responses. It was only in the most seriously disturbed patients that both accurately and inaccurately perceived human responses were at lower developmental levels. Findings are discussed in terms of the nature and the function of experiences of reality and the importance of assessing the content and formal properties of object representation in studying normal development and psychopathology. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Episodic and semantic knowledge in emotional self-report: Evidence for two judgment processes.

Three studies involving 3 participant samples (Ns = 39, 55, and 53) tested the hypothesis that people retrieve episodic emotion knowledge when reporting on their emotions over short (e.g., last few hours) time frames, but that they retrieve semantic emotion knowledge when reporting on their emotions over long (e.g., last few months) time frames. Support for 2 distinct judgment strategies was based on judgment latencies (Studies I and 2) and priming paradigms (Studies 2 and 3). The authors suggest that self-reports of emotion over short versus long time frames assess qualitatively different sources of self-knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for preserved emotional memory in normal older persons.

Emotion has been shown to have a modulatory effect on declarative memory. Normal aging is associated with a decline in declarative memory, but whether aging might affect the influence of emotion on memory has not been established. To investigate this, we administered a task that provides a detailed assessment of emotional memory to 80 neurologically normal adults ranging in age from 35 to 85 years. Across ages, memory performance was found to be modulated by the emotional significance of stimuli in a comparable manner (improved memory for gist, compromised memory for visual detail), despite an overall decline in memory performance with increasing age. The results raise the interesting possibility that aging has a differential effect on hippocampal versus amygdala function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Face perception in high-functioning autistic adults: Evidence for superior processing of face parts, not for a configural face-processing deficit.

Configural processing in autism was studied in Experiment 1 by using the face inversion effect. A normal inversion effect was observed in the participants with autism, suggesting intact configural face processing. A priming paradigm using partial or complete faces served in Experiment 2 to assess both local and configural face processing. Overall, normal priming effects were found in participants with autism, irrespective of whether the partial face primes were intuitive face parts (i.e., eyes, nose, etc.) or arbitrary segments. An exception, however, was that participants with autism showed magnified priming with single face parts relative to typically developing control participants. The present findings argue for intact configural processing in autism along with an enhanced processing for individual face parts. The face-processing peculiarities known to characterize autism are discussed on the basis of these results and past congruent results with nonsocial stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of task-irrelevant cues and reinforcement delay on choice-escape learning following inescapable shock: Evidence for a deficit in selective attention.

Five experiments with 152 male albino rats examined the conditions under which choice-escape learning in an automated Y-maze is impaired by pretreatment with inescapable shock. Ss exposed to inescapable shock made more errors and responded more slowly than did controls only when shock termination was delayed and task-irrelevant cues were present during choice-escape training. Findings are discussed in terms of information processing and neurochemical consequences of exposure to inescapable shock. It is suggested that the concurrent manipulation of irrelevant cues and reinforcement delay may have masked the choice contingency and increased task difficulty. Other possible explanations of the results include lessened attention to proprioceptive stimuli, differences in arousal levels between conditions, and depletion of norepinephrine in the locus coeruleus following inescapable shock. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gustatory thalamus lesions eliminate successive negative contrast in rats: Evidence against a memory deficit.

Successive negative contrast is the exaggerated reduction of licking that occurs when rats expecting a high-value reward are given a low-value reward. This effect is typically investigated with a 24-hr retention interval between access periods. The present experiment tested the hypothesis that the absence of successive negative contrast in rats with bilateral lesions of the gustatory thalamus (GT) is due to a memory deficit. The results argue against this hypothesis by showing that, irrespective of retention-interval duration (7.5 min, 15 min, 45 min, 180 min, or 24 hr), lesioned rats failed to show successive negative contrast. As such, the data are consistent with the alternative view that GT lesions specifically disrupt the reward comparison mechanism that underlies successive negative contrast. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magical ideation and social anhedonia as predictors of psychosis proneness: a partial replication

The authors compared college students identified by high scores on the Magical Ideation Scale (M. Eckblad & L. J. Chapman, 1983) and the Revised Social Anhedonia Scale (MagSoc; n = 28; M. Eckblad, L. J. Chapman, J. P. Chapman, & M. Mishlove, 1982) with control participants (n = 20) at a 10-year follow-up assessment in an attempt to replicate L. J. Chapman, J. P. Chapman, T. R. Kwapil, M. Eckblad, and M. C. Zinser's (1994) report of heightened psychosis proneness in MagSoc individuals. The MagSoc group exceeded the control group on severity of psychotic-like experiences; ratings of schizotypal, paranoid, and borderline personality disorder symptoms; and rates of mood and substance use disorders. Two of the MagSoc participants but none of the control participants developed psychosis during the follow-up period (a nonsignificant difference). Consistent with L. J. Chapman et al.'s findings, the groups did not differ on rates of personality disorders or relatives with psychosis.     

Psychological deficit in schizophrenia: I. Affect, reinforcement, concept attainment.

This, the 1st of 2 papers reviewing laboratory studies of psychological deficit in schizophrenia, considers the effects of social censure, affective stimuli, cooperation, urging, and verbal and nonverbal reinforcers on performance on a variety of tasks. Disturbance i concept formation is evaluated in terms of: loss of abstract attitude, communication disturbance, regression, and the consequence of erratic attention. Finally, various theories of schizophrenia deficit are evaluated. Although motivational constructs cannot be wholly dismissed, interference theory is generally more comprehensive and parsimonious. Many specific hypotheses of interference theory still need to be substantiated by experiment, however. (130 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parabrachial nucleus lesions and conditioned taste aversion: Evidence supporting an associative deficit.

Three experiments examined the conditioned taste aversion (CTA) deficit that occurs following electrolytic lesions of the parabrachial nucleus (PBN). In Exp 1, lesioned rats failed to avoid either a gustatory or an olfactory stimulus that had been paired with lithium chloride-induced toxicosis. In Exp 2, however, all rats learned a conditioned flavor preference. Finally, in Exp 3, all controls and 7 of the 12 lesioned rats learned a conditioned place aversion. Together, these results demonstrate that the disruption of CTA in lesioned rats cannot be ascribed to an inability to process either gustatory or visceral afferent information per se. Rather, the data suggest that PBN-lesioned rats are unable to form a specific association between gustatory and visceral cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing irrational beliefs and emotional distress: Evidence and implications of limited discriminant validity.

In the present study of adult mental health center outpatients, we examined the discriminant validity of measures of irrational beliefs. The Irrational Beliefs Test (IBT; Jones, 1968) and the Rational Behavior Inventory (RBI; Shorkey & Whiteman, 1977) were highly correlated but were equally highly correlated with self-report measures of depression and anxiety. Thus, rather than assessing beliefs that are in turn correlated with emotional distress, the IBT and RBI may themselves actually assess general dysphoria or neuroticism. Further analyses suggested that contamination with neuroticism may account for correlations between beliefs and dysfunctional emotions. Some specific beliefs, however, demonstrated associations with depression and anger that could not be accounted for by contamination with neuroticism. Results are discussed in terms of empirical support for the rational–emotive model and our ability to test its basic assumptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)