A comparison of kainic acid plus colchicine and ibotenic acid-induced hippocampal formation damage on four configural tasks in rats.

J. W. Rudy and R. J. Sutherland (1989) suggested that the hippocampal formation (HF) is necessary for performance of configural tasks and that rats with kainic acid?+?colchicine (K–C) damage to the HF were impaired on the negative patterning problem (A+, B+, AB–). However, M. Gallagher and P. C. Holland (1992) found spared performance on a similar task (AC+, B+, AB–, C–) when ibotenic acid (IBO) was used. This study compared the effects of K–C and IBO-induced HF damage on 4 configural tasks: (a) negative patterning, (b) the Gallagher-Holland task, (c) transverse patterning, and (d) place learning. Rats with IBO lesions performed like controls on the Gallagher-Holland task (replicating M. Gallagher & P. C. Holland) but were impaired on negative patterning, transverse patterning, and place learning. In contrast, rats with K–C lesions were impaired on all 4 tasks. The implications of these results for theories of HF function are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rats with damage to the hippocampal-formation are impaired on the transverse-patterning problem but not on elemental discriminations.

We assessed the effects of hippocampal-formation (HF) damage on the rat's ability to learn two sets of concurrent visual discriminations. Each set included three problems. One set, called the transverse-patterning problem, was constructed so that each choice stimulus was ambiguous; sometimes it was the correct (+) and sometimes it was the incorrect (–) choice as follows: A+ vs B–, B+ vs C–, and C+ vs A–. It could not be solved unless rats used configural associations. The stimuli were not ambiguous in the second, elemental problem set, A+ vs B–, C+ vs D–, and E+ vs F–. Rats could solve this set without the use of configural associations. Rats with HF damage solved the set of elemental problems, but their performance on the transverse-patterning problem was impaired. These results support Sutherland and Rudy's (see record 1989-38933-001) theory that the hippocampal formation is critical for the acquisition of configural associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preserved negative patterning and impaired spatial learning in pigeons (Columba livia) with lesions of the hippocampus.

Pigeons (Columba livia) with bilateral electrolytic lesions of the hippocampus and area parahippocampalis were compared with control pigeons on 2 tasks: negative patterning and delayed spatial alternation. Negative patterning demands configural stimulus representations for its successful solution. The only effect of hippocampal lesions on this task was an increased response rift to the rewarded stimuli. On the delayed spatial alternation task, hippocampal birds showed deficits relative to controls. Differences in the results of prior studies on negative patterning appear to be due to different response requirements to the nonreinforced stimuli. These results are consistent with prior work with rats and suggest that the avian hippocampus is essential for spatial memory and response inhibition but is not involved in configural learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of partially and continuously reinforced pretraining on choice and latency measures in the rat.

Gave 116 male Long-Evans rats, in 2 experiments, either continuously reinforced or partially reinforced pretraining prior to discrimination training. Pretraining was given to both stimuli to be discriminated, to one of the stimuli, to different stimuli, or to no stimuli and was compared to a control condition with no pretraining. There was little effect of pretraining on choice measures of learning and varied effects on latency measures. Latencies were most affected by partially reinforced pretraining. Although the choice data supported N. S. Sutherland and N. J. MacKintosh's 1971 attentional theory and the latency data offered partial support for A. Amsel and J. S. Ward's (see record 2011-19151-001) frustration theory, it is noted that neither theory could handle the data that the other relies upon. Discrepancies found between choice and latency measures suggest that they measure 2 different processes in discrimination learning. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Cortico-hippocampal representations in simultaneous odor discrimination: A computational interpretation of Eichenbaum, Mathews, and Cohen (1989).

A previous model of hippocampal region function in classical conditioning is generalized to H. Eichenbaum, A. Fagan, P. Mathews, and N. J. Cohen's (see record 1988-28895-001) and H. Eichenbaum, A. Fagan, and N. J. Cohen's (see record 1990-09261-001) simultaneous odor discrimination studies in rats. The model assumes that the hippocampal region forms new stimulus representations that compress redundant information while differentiating predictive information; the piriform (olfactory) cortex meanwhile clusters similar and co-occurring odors. Hippocampal damage interrupts the ability to differentiate odor representations, while leaving piriform-mediated odor clustering unchecked. The result is a net tendency to overcompress in the lesioned model. Behavior in the model is very similar to that of the rats, including lesion deficits, facilitation of successively learned tasks, and transfer performance. The computational mechanisms underlying model performance are consistent with the qualitative interpretations suggested by Eichenbaum et al to explain their empirical data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Septal influences on operant responding in the rat.

In 3 experiments with a total of 74 male albino Sprague-Dawley rats, the afferent and efferent connections of the septum with the hippocampus (fornix) or with the hypothalamus and lower brain stem (medial forebrain bundle) were transected by means of an encephalotome near the point where these pathways enter or leave the septal area. A transection of the fornix that produced minimal direct damage to cellular components of the septum or hippocampus reproduced the effects of large septal lesions on responding in several temporally defined paradigms that involve periods of response suppression (DRL, discriminated Sidman avoidance, FI). Transection of the medial forebrain bundle fibers that interconnect the septum with the hypothalamus and lower brain stem did not affect behavior in any of these paradigms. It is suggested that these observations be viewed in the context of the results of earlier investigations by the authors (see record 1974-27002-001), R. J. Carey (see record 1969-13784-001), and J. M. McDougall et al (see record 1969-13791-001), which showed that transection of the medial forebrain bundle reproduces several other components of the septal lesion syndrome. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual conditioning and auditory cue conditioning dissociate during development.

Following a single shock presentation, fear conditioning to an auditory cue and to the experimental context was assessed by measuring the rat's tendency to freeze. On the conditioning day, 18-day-old rats showed as much freezing to the auditory cue as older rats. However, 18-day-old pups displayed much less freezing to the training context than did pups 21–27 days old. The developmental dissociation between contextual and auditory cue conditioning parallels the dissociation produced by damage to the adult rat's hippocampal system (J. J. Kim and M. S. Fanselow, 1992; R. G. Phillips and G. E. LeDoux, 1992). The dissociation is also consistent with the developmental hypothesis that the configural association system develops late in comparison with the elemental association system (J. W. Rudy, 1991, 1992). The implications of the findings for the maturation of the neural components of the fear-conditioning circuit also are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective hippocampal lesions in rats disrupt acquisition and retention of a positive patterning discrimination

To determine the contribution of the hippocampus in the processing of a configural positive patterning discrimination (PPD) task, discrimination between reinforced presentations of a tone plus light compound stimulus and nonreinforced presentations of each of its components (TL+/T-,L-) was examined using a conditioned-suppression paradigm. In the first experiment, rats demonstrated a rapid acquisition of the PPD with an appropriate discriminative responding. Rats submitted to posttraining hippocampal lesions (using multiple injections of ibotenic acid) were no longer able to master correctly the previously solved discrimination, demonstrating significant differences in their response rates during the 2 never-reinforced elemental stimulus presentations. In Experiment II, lesioned rats were not able to correctly learn the PPD, demonstrating the same pattern of responding as in Experiment I. These rats were also severely disrupted in a radial maze elimination task. Experiment IIIa indicated that, in a simple conditioning task (T+, L+), normal rats acquired a rapid conditioned suppression for both stimuli, with the tone being slightly more susceptible to conditioning than the light stimulus. In Experiment IIIb, conditioning to the compound tone plus light stimulus led to a clear conditioning to the tone and almost no conditioning to the light, suggesting an overshadowing from the tone to the light. Similar results were obtained in rats with hippocampal lesions. These results strongly suggest that the disruption showed by rats with hippocampal lesions in the PPD task cannot be due to an alteration of the relative salience of the stimulus. The inability of rats with hippocampal lesions to solve correctly the PPD is due to difficulties in eliminating responding to some unimportant events of the situation, reflecting a deficit in selective attention processes rather than in an ability to process configural stimuli. In the discussion, the putative role of the hippocampus in selective attentional processes is more fully discussed.     

The sea horse comes of age: Theoretical comment on Rehbein, Killiany, and Mahut (2005) and Killiany, Rehbein, and Mahut (2005).

Impairments in various aspects of learning and memory have been ascribed to the effects of damage to the hippocampal formation in adult nonhuman primates. Whether these effects reflect disturbance of a unitary process or multiple processes within the hippocampus and whether other systems may participate in these functions is unclear. After making hippocampal ablations in infant rhesus monkeys (Macaca mulatta), L. Rehbein, R. Killiany, and H. Mahut (2005) (see record 2005-06959-001) and R. Killiany, L. Rehbein, and H. Mahut (2005) (see record 2005-06959-002) reported a dissociation of effect between tasks of recognition memory and contextual retrieval (impaired) and associative learning (spared). The findings point to an ontogenetic dissociation of function within the hippocampal formation and, at the same time, support the view of the coexistence of at least two neural systems that underlie memory and learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dimensional information facilitates the utilization of configural information: A test of the Castellan-Edgell and the Gluck-Bower models.

In 4 experiments involving learning in a probabilistic environment (a nonmetric multiple-cue probability learning environment) the authors found that utilization of relevant configural information was facilitated when any relevant dimensions were part of the relevant pattern. Relevant configural information in an environment with no relevant dimensions was as highly utilized as when the pattern contained the relevant dimension. With 2 relevant dimensions, the dimension within the relevant pattern was more highly utilized than the dimension not in the relevant pattern. Both N. J. Castellan and S. E. Edgell's (see record 1974-10165-001) hypothesis testing model and M. A. Gluck and G. H. Bower's (see record 1989-07449-001) connectionist model were unable to fit several aspects of the findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Systematic comparison of the effects of hippocampal and fornix-fimbria lesions on acquisition of three configural discriminations

The effects of lesions to the hippocampal system on acquisition of three different configural tasks by rats were tested. Lesions of either the hippocampus (kainic acid/colchicine) or fornix-fimbria (radiofrequency current) were made before training. After recovery from surgery, rats were trained to discriminate between simple and compound-configural cues that signaled the availability or nonavailability of food when a bar was pressed. When positive cues were present, one food pellet could be earned by pressing a lever after a variable time had elapsed. The trial terminated on food delivery (variable interval 15 s). This procedure eliminates some possible alternative explanations of the results of previous experiments on configural learning. Hippocampal lesions increased rates of responding and retarded acquisition of a negative patterning task (A+, B+, AB-); using a ratio measure of discrimination performance these lesions had a milder retarding effect on a biconditional discrimination (AX+, AY-, BY+, BX-), and they had no effect on a conditional context discrimination (X: A+, B-; Y: A-, B+). Fornix-fimbria lesions did not affect acquisition of any of these tasks but increased rates of responding. The results suggest that several task parameters determine the involvement of the hippocampus in configural learning; however, all tasks tested can also be learned to some extent in the absence of an intact hippocampal system, presumably by other learning/memory systems that remain intact following surgery. The lack of effect of fornix-fimbria lesions on any of these tasks suggests that retrohippocampal connections with other brain areas may mediate hippocampal contributions to the learning of some configural tasks. An analysis of these results and of experiments on spatial learning situations suggests that involvement of the hippocampus is a function of the degree to which correct performance depends on a knowledge of relationships among cues in a situation.     

Tuning out irrelevancy? Comments on Solomon's temporal mapping view of the hippocampus.

In his analysis of the present author's series of studies on the role of the hippocampus in spatial information processing (A. H. Black, L. Nadel, and J. O'Keefe; 1974, 1975, 1976, 1979), P. R. Solomon (see record 1980-04864-001) proposed an extension to the cognitive map theory of hippocampal function. He cites evidence drawn mainly from the literature on the classical conditioning of the rabbit's nictitating membrane response, which he claims can not be satisfactorily explained within the framework of the present theory. The present article shows that the deficits following hippocampal lesions can be predicted from understanding the role of place learning in each paradigm and shows that electrophysiological data are open to different interpretation. It is concluded that the data cited by Solomon do not require any modification of the theory. (2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comments on Paivio's imagery theory.

Discusses the differences between A. Paivio's (see record 1976-01839-001) imagery theory and a model of simultaneous and successive processing proposed by J. P. Das et al (see record 1975-08765-001). The latter model, which emphasizes the primacy of cognitive processes as opposed to task materials or instructions, is viewed as more sound. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression and the search for negative evaluations: More evidence of the role of self-verification strivings.

W. B. Swann et al (see record 1992-27469-001) suggested that depressed and dysphoric persons verify their self-conceptions by seeking rather negative appraisals. J. M. Hooley and J. E. Richters (see record 1992-27439-001) and L. B. Alloy and A. J. Lipman (see record 1992-27420-001) have worried that (1) idiosyncratic features of the Swann et al participants and design may have produced their effects and (2) Swann et al presented no evidence that self-verification strivings are motivated. The authors address these issues empirically. Study 1 showed that 20 dysphoric participants preferred interacting with a person who appraised them unfavorably over participating in another study, in comparison with 30 nondysphorics. Study 2 revealed that 26 dysphoric persons responded to feedback that challenged their negative self-view by working to reaffirm their low self-esteem, in comparison with 47 nondysphorics. These findings support the notion that at some level depressed and dysphoric persons want rather negative appraisals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"A bit more light on Ferenczi and Freud": Response to Tabin.

Comments on the response by J. K. Tabin (see record 1995-43797-001) to the critique by L. Aron and J. B. Frankel (see record 1994-41100-001) of her article on Freud's motivation for rethinking his seduction theory (see record 1994-05584-001). Freud's priority in citing the relationship between splitting of the ego and childhood sexual trauma and his treatment of Ferenczi are highlighted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Effects of age and gender on perceived facial attractiveness": Reply.

Responds to comments by R. H. Bradshaw et al (see record 1995-01642-001) on B. McLellan and S. J. McKelvie's study (see record 1993-45212-001) investigating the effects of age and gender on attractiveness of photographs of faces. Although the major result of this study was a negative relationship between age and perceived attractiveness, the authors conclude that sociobiological theory received qualified support, with 4 out of 6 revised predictions confirmed. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Got a minute? Attentional limits revisited.

Responds to comments by R. C. Tees (see record 1991-03035-001), J. G. Adair (see record 1991-03013-001), J. E. Grusec (see record 1991-03021-001), K. Danziger (see record 1991-03016-001), L. P. Mos (see record 1991-03027-001), H. J. Stam (see record 1991-03033-001), and V. Vikis-Freilbergs (see record 1991-03039-001) on W. Thorngate's (see record 1991-03036-001) contention that the overproduction of psychological literature will lead to fragmentation of the discipline. As the works of psychologists proliterate, their scientific truth may capture less attention than their practical importance or personal interest. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the validity of psychoanalytic constructs in the 20th century.

Responds to comments by F. Dumont (see record 1994-42094-001) about J. J. Magnavita's (see record 1993-42219-001) discussion of Freud's purported discovery of unconscious processes. Dumont underestimates the extent to which Freud both synthesized and advanced the knowledge of unconscious processes to create a metapsychological system that forms the foundation of many current psychotherapy models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Encounter research.

Refers readers interested in the article by D. Hartley et al (see record 1977-01609-001) to 4 articles on encounter research by M. J. Diamond and J. L. Shapiro (see record 1976-05062-001), J. Rowan (see record 1976-02670-001), W. Schutz (see record 1976-02672-001), and P. B. Smith (see record 1976-02673-001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)