Using pavlovian higher-order conditioning paradigms to investigate the neural substrates of emotional learning and memory. (73/4689)

In first-order Pavlovian conditioning, learning is acquired by pairing a conditioned stimulus (CS) with an intrinsically motivating unconditioned stimulus (US; e.g., food or shock). In higher-order Pavlovian conditioning (sensory preconditioning and second-order conditioning), the CS is paired with a stimulus that has motivational value that is acquired rather than intrinsic. This review describes some of the ways higher-order conditioning paradigms can be used to elucidate substrates of learning and memory, primarily focusing on fear conditioning. First-order conditioning, second-order conditioning, and sensory preconditioning allow for the controlled demonstration of three distinct forms of memory, the neural substrates of which can thus be analyzed. Higher-order conditioning phenomena allow one to distinguish more precisely between processes involved in transmission of sensory or motor information and processes involved in the plasticity underlying learning. Finally, higher-order conditioning paradigms may also allow one to distinguish between processes involved in behavioral expression of memory retrieval versus processes involved in memory retrieval itself.  (+info)

Effects of the selective M1 muscarinic receptor antagonist dicyclomine on emotional memory. (74/4689)

The nonselective muscarinic antagonist scopolamine is known to impair the acquisition of some learning tasks such as inhibitory avoidance. There has been recent research into the effects of this drug in contextual fear conditioning and tone fear conditioning paradigms. The purpose of the present study was to assess the role of the selective M1 muscarinic antagonist dicyclomine in these paradigms and in the inhibitory avoidance test. Rats were administered different doses of dicyclomine or saline 30 min before acquisition training. The animals were tested 24 hr later, and it was observed that 16 mg/kg of dicyclomine impaired both contextual fear conditioning and inhibitory avoidance. However, dicyclomine (up to 64 mg/kg) did not affect tone fear conditioning. These results suggest that the selective M1 muscarinic antagonist dicyclomine differentially affects aversively motivated tasks known to be dependent on hippocampal integrity (such as contextual fear conditioning and inhibitory avoidance) but does not affect similar hippocampus-independent tasks.  (+info)

The functional neuroanatomy of social behaviour: changes in cerebral blood flow when people with autistic disorder process facial expressions. (75/4689)

Although high-functioning individuals with autistic disorder (i.e. autism and Asperger syndrome) are of normal intelligence, they have life-long abnormalities in social communication and emotional behaviour. However, the biological basis of social difficulties in autism is poorly understood. Facial expressions help shape behaviour, and we investigated if high-functioning people with autistic disorder show neurobiological differences from controls when processing emotional facial expressions. We used functional MRI to investigate brain activity in nine adults with autistic disorder (mean age +/- standard deviation 37 +/- 7 years; IQ 102 +/- 15) and nine controls (27 +/- 7 years; IQ 116 +/- 10) when explicitly (consciously) and implicitly (unconsciously) processing emotional facial expressions. Subjects with autistic disorder differed significantly from controls in the activity of cerebellar, mesolimbic and temporal lobe cortical regions of the brain when processing facial expressions. Notably, they did not activate a cortical 'face area' when explicitly appraising expressions, or the left amygdala region and left cerebellum when implicitly processing emotional facial expressions. High-functioning people with autistic disorder have biological differences from controls when consciously and unconsciously processing facial emotions, and these differences are most likely to be neurodevelopmental in origin. This may account for some of the abnormalities in social behaviour associated with autism.  (+info)

Cortical activation patterns of affective speech processing depend on concurrent demands on the subvocal rehearsal system. A DC-potential study. (76/4689)

In order to delineate brain regions specifically involved in the processing of affective components of spoken language (affective or emotive prosody), we conducted two event-related potential experiments. Cortical activation patterns were assessed by recordings of direct current components of the EEG signal from the scalp. Right-handed subjects discriminated pairs of declarative sentences with either happy, sad or neutral intonation. Each stimulus pair was derived from two identical original utterances that, due to digital signal manipulations, slightly differed in fundamental frequency (F0) range or in duration of stressed syllables. In the first experiment, subjects were asked: (i) to denote the original emotional category of each sentence pair and (ii) to decide which of the two items displayed stronger emotional expressiveness. Participants in the second experiment were asked to repeat the utterances using inner speech during stimulus presentation in addition to the discrimination task. In the absence of inner speech, a predominant activation of right frontal regions was observed, irrespective of emotional category. In the second experiment, a bilateral activation with left frontal preponderance emerged from discrimination during additional performance of inner speech. Compared with the first experiment, a new pattern of acoustic signal processing arose. A relative decrease of brain activity during processing of F0 stimulus variants was observed together with increased activation during discrimination of duration-manipulated sentence pairs. Analysis of behavioural data revealed no significant differences in evaluation of expressiveness between the two experiments. We conclude that the topographical shift of cortical activity originates from left hemisphere (LH) mechanisms of speech processing that centre around the subvocal rehearsal system as an articulatory control component of the phonological loop. A strong coupling of acoustic input and (planned) verbal output channel in the LH is initiated by subvocal articulatory activity like inner speech. These neural networks may provide interpretations of verbal acoustic signals in terms of motor programs and facilitate continuous control of speech output by comparing the signal produced with that intended. Most likely, information on motor aspects of suprasegmental signal characteristics contributes to the evaluation of affective components of spoken language. In consequence, the right hemisphere (RH) holds a merely relative dominance, both for processing of F0 and for evaluation of emotional significance of sensory input. Psychophysically, an important determinant on expression of lateralization patterns seems to be given by the degree of communicative demands such as solely perceptive (RH) or perceptive and verbal-expressive (RH and LH).  (+info)

Evaluation of the needs of male carriers of mutations in BRCA1 or BRCA2 who have undergone genetic counseling. (77/4689)

To date, the concerns of men at risk of inheriting a BRCA1 mutation or a BRCA2 mutation have received little attention. It had been anticipated that few men would be interested in predictive testing when a BRCA mutation was identified in their family. However, these men are often affected emotionally by diagnoses of breast cancer in their relatives and may themselves harbor fears that cancer will develop. Male carriers of BRCA1/2 mutations are at increased risk of development of cancers of several types, including those of the breast and prostate. We conducted an evaluation of the needs and experiences of 59 male carriers of BRCA1/2 mutations followed at either the University of Toronto or Creighton University. We assessed their motivations for seeking genetic counseling and testing, involvement in family discussions of breast and ovarian cancer, risk perception, changes in cancer-screening practices, and overall satisfaction with the genetic-counseling process. The principal motivation for seeking genetic counseling was concern for their daughters. The majority (88%) of men participated in family conversations about breast and ovarian cancer, and 47% participated in conversations about prophylactic surgery. Most men believed that they were at increased risk of development of cancer (prostate, breast, colorectal, and skin cancers). However, fewer than one-half (43%) of the men with no previous diagnosis of cancer stated that their prostate cancer-surveillance practices had changed after they had received genetic test results. More than one-half (55%) had intrusive thoughts about their cancer risk. Although levels of satisfaction were high, practitioners should be aware of (a) potential pressures influencing men to request predictive testing, (b) the difficulties that men encounter in establishing surveillance regimens for breast and prostate cancer, and (c) the general lack of information about men's particular experiences in the medical community.  (+info)

Enhancement of declarative memory associated with emotional content in a Brazilian sample. (78/4689)

Several studies have documented that emotional arousal may enhance long-term memory. This is an adaptation of a paradigm previously used in North American and European samples in investigations of the influence of emotion on long-term retention. A sample of 46 healthy adults of high and low educational levels watched a slide presentation of stories. A randomly assigned group watched a story with an arousing content and another group watched a neutral story. The stories were matched for structure and comprehensibility and the set and order of the 11 slides were the same in both conditions. Immediately after viewing the slide presentation, the participants were asked to rate the emotionality of the narrative. The arousing narrative was rated as being more emotional than the neutral narrative (t(44) = -3.6, P<0.001). Ten days later subjects were asked to remember the story and answer a multiple-choice questionnaire about it. The subjects who watched the arousing story had higher scores in the free recall measure (t(44) = -2.59, P<0. 01). There were no differences between groups in the multiple-choice test of recognition memory (t(44) = 0.26). These findings confirm that an emotional arousing content enhances long-term declarative memory and indicate the possibility of applying this instrument to clinical samples of various cultural backgrounds.  (+info)

Ultrasonic isolation calls in genetically high- and low-emotional rat pups. (79/4689)

The present study was undertaken to investigate the relationship between the emotionality and the modulation of ultrasonic vocalizations in Tsukuba High Emotional (THE) and Tsukuba Low Emotional (TLE) strain rat pups 3-18 days old. The THE pups, while isolated from their dam and littermates and placed in a cold environment, emitted ultrasonic isolation calls at a high rate until day 15. In contrast, ultrasound production was at a consistently low level throughout the test period in the TLE pups. The ultrasonic isolation calls of THE pups were attenuated to the same level as those of the TLE pups after administration of diazepam (1 mg/kg, s.c.), a benzodiazepine receptor agonist, at 6 and 12 days of age. These findings suggest that the high emotionality of the rat pups was reflected largely by the emission of ultrasounds in response to isolation distress rather than the number of the benzodiazepine receptors in the brain that might play a role in physiologic mediation of the rat pup isolation call.  (+info)

Impact of emotion on memory. Controlled study of the influence of emotionally charged material on declarative memory in Alzheimer's disease. (80/4689)

BACKGROUND: In an earlier study we showed that a powerful emotional experience (the Kobe earthquake) reinforced memory retention in patients with Alzheimer's disease, but we could not control factors other than the emotional impact of the earthquake. AIMS: To test our previous findings in a controlled experimental study. METHOD: Recall tests consisting of two short stories were administered to 34 patients with Alzheimer's disease and 10 normal subjects. The two stories were identical except for one passage in each story: one was emotionally charged (arousing story) and the other (neutral story) was not. RESULTS: In both groups, the emotionally charged passage in the arousing story was remembered better than the counterpart in the neutral story. In addition, the extent of the memory improvement was similar in the subjects and in the controls. CONCLUSIONS: The results provide further evidence that emotional arousal enhances declarative memory in patients with Alzheimer's disease, and give a clue to the management of people with dementia.  (+info)