ABSTRACT We examined the capacity of human subjects to accurately identify the emotional content ... more ABSTRACT We examined the capacity of human subjects to accurately identify the emotional content in verbal descriptions of various situations. Six emotions were studied: happiness, surprise, fear, ...
The purpose of this experiment was to study the accuracy of judgment of facial expressions of emo... more The purpose of this experiment was to study the accuracy of judgment of facial expressions of emotions that were displayed for very brief exposure times. Twenty university students were shown facial stimuli that were presented for durations ranging from 10 to 50 msec. The data showed that accuracy of judgment reached a fairly high level even at very brief exposure times and that human observers are especially competent to process very rapid changes in facial appearance.
The purpose of this study was to compare the recognition performance of children who identified f... more The purpose of this study was to compare the recognition performance of children who identified facial expressions of emotions using adults' and children's stimuli. The subjects were 60 children equally distributed in six subgroups as a function of sex and three age levels: 5, 7, and 9 years. They had to identify the emotion that was expressed in 48 stimuli
The aim of the experiment was to study the relation between accuracy of judgment of facial expres... more The aim of the experiment was to study the relation between accuracy of judgment of facial expressions of emotions and time for judgment. The results for 34 college students confirmed previous data showing high performance in identification of all emotions, although there were some important differences between emotions. Also, times for judgment were longer for the emotions which were more difficult to identify.
The aim of this experiment was to study the identification of the facial expressions of six emoti... more The aim of this experiment was to study the identification of the facial expressions of six emotions in French-speaking québécois subjects. Two methods of stimuli presentation were used. The results showed high identification levels that were comparable to those of others working with various cultures. The simultaneous presentation of a facial expression and of the same face with a neutral expression had no effect on the subjects' accuracy of judgment. Female subjects had a higher identification level of disgust than male subjects. Finally, the analysis of the distribution of judgment errors partially confirmed previous data concerning confusions of emotions.
Monkeys with removals of medial temporal lobe (MTL) structures are widely recognized as valid mod... more Monkeys with removals of medial temporal lobe (MTL) structures are widely recognized as valid models of human global anterograde amnesia, a syndrome that arises consequent to damage to a finite set of brain structures situated in the medial temporal lobe and/or medial diencephalon. However, a comparison of memory deficits in human and nonhuman primates with MTL damage has presented a long-standing puzzle. Whereas amnesic patients are impaired in learning object discrimination problems, monkeys with MTL damage are typically not. One possible explanation for this difference is that object discrimination tasks for humans and monkeys differ in that the former but not the latter requires the use of contextual information. If this analysis is correct, monkeys with MTL damage might be disadvantaged in learning to discriminate similar objects presented in different contexts. To test this possibility, we evaluated the effects of excitotoxic lesions of one of the MTL structures, the hippocampus, on the rate of learning of discrimination problems embedded within unique contexts. Monkeys with hippocampal lesions were impaired relative to controls in learning object discrimination problems of this type. These findings strongly support the idea that the difference in the effect on object memory of MTL damage in human and nonhuman primates is due to a difference in the opportunity to employ contextual cues rather than to a difference in the organization of memory.
In the present experiment, sham-operated (SH) and fornix-transected (FX) rats were trained on a n... more In the present experiment, sham-operated (SH) and fornix-transected (FX) rats were trained on a new nonspatial, odor-guided task. On each session, eight odor pairs were presented twice. On the first occurrence of a pair, rats were reinforced for pushing the container (go response) in which the olfactory stimuli were placed. On the second occurrence, they were not reinforced and had to refrain from responding (no-go response) to be scored as success. Rats were first trained to criterion on odor pairs made of replicates of the same odor (S pairs). Then they were trained to criterion on pairs made of different odors, each member of the pair overlapping with that of another pair (O pairs) and finally, on pairs of different odors with no overlap (NO pairs). The results showed that the number of sessions to reach criterion was significantly higher in FX than in SH rats during training on O pairs, but not during training on S or on NO pairs. These findings are consistent with the configural (Rudy and Sutherland, 1995: Hippocampus 5:375-389) or relational (Eichenbaum et al., 1994: Behav Brain Sci 17:449-518) account of the hippocampal memory function.
The contribution of the dorsal subiculum (DS) and of the dorsal hippocampus (DH) to memory for di... more The contribution of the dorsal subiculum (DS) and of the dorsal hippocampus (DH) to memory for distinct and overlapping visual stimuli was examined. Rats with selective lesions of the DS or the DH were compared to sham-operated rats on a delayed matching-to-place task guided by distal visual cues in a modified radial-arm maze. Overlapping distal visual cues could be perceived from three arm entrances (adjacent arms) and a unique set of distal cues were more likely to be seen from the other two arm entrances (distinct arms). Rats with DS lesions were impaired on trials with baited adjacent arms, but not on trials with baited distinct arms. Rats with DH lesions were impaired on both types of trials. These results suggest that the DS and the DH are necessary for pattern separation and that they may have different contributions to memory.
As a preliminary step towards the use of natural odorants in laboratory imprinting studies, olfac... more As a preliminary step towards the use of natural odorants in laboratory imprinting studies, olfactory learning by young Atlantic salmon, Salmo salar, was assessed by heart rate conditioning to L-cysteine (3.8 × 10−4 M). Fish were successfully conditioned and decelerated their heart rate to L-cysteine compared with that of a control group tested under random pairing sequences of L-cysteine and an electrical stimulation. The cardiac conditioning response and sensitivity of fish to L-cysteine was unaffected by a procedure of curarization. Cardiac performance of fish conditioned to L-cysteine was also compared with that of other groups of fish exposed to four different odorous substances. The conditioned response increased significantly across trials when morpholine, L-cysteine, or L-phenylalanine was used as the conditioning stimulus, but remained unchanged throughout the experiment in the presence of L-serine or L-threonine.
Polymorphisms in the gene encoding the brain serotonin synthesis enzyme Tph2 have been identified... more Polymorphisms in the gene encoding the brain serotonin synthesis enzyme Tph2 have been identified in mental illnesses, with co-morbidity of substance use disorder. However, little is known about the impact of Tph2 gene variants on addiction. Mice expressing a human Tph2 loss of function variant were used to investigate consequences of aversive conditions on ethanol intake. Mice were familiarized either with ethanol or a solution containing both ethanol and the bittering agent quinine. Effect of familiarization to ethanol or an ethanol-quinine solution was then evaluated using a two-bottles preference test in Tph2-KI and control littermates. Mice from both genotypes displayed similar levels of ethanol consumption and quinine avoidance when habituated to ethanol alone. In contrast, addition of quinine to ethanol during the familiarization period resulted in a reduction of avoidance for the quinine-ethanol solution only in mutant mice. These results indicate that loss of function mutation in Tph2 results in greater motivation for ethanol consumption under aversive conditions and may confer enhanced sensitivity to alcohol use disorder.
ABSTRACT We examined the capacity of human subjects to accurately identify the emotional content ... more ABSTRACT We examined the capacity of human subjects to accurately identify the emotional content in verbal descriptions of various situations. Six emotions were studied: happiness, surprise, fear, ...
The purpose of this experiment was to study the accuracy of judgment of facial expressions of emo... more The purpose of this experiment was to study the accuracy of judgment of facial expressions of emotions that were displayed for very brief exposure times. Twenty university students were shown facial stimuli that were presented for durations ranging from 10 to 50 msec. The data showed that accuracy of judgment reached a fairly high level even at very brief exposure times and that human observers are especially competent to process very rapid changes in facial appearance.
The purpose of this study was to compare the recognition performance of children who identified f... more The purpose of this study was to compare the recognition performance of children who identified facial expressions of emotions using adults' and children's stimuli. The subjects were 60 children equally distributed in six subgroups as a function of sex and three age levels: 5, 7, and 9 years. They had to identify the emotion that was expressed in 48 stimuli
The aim of the experiment was to study the relation between accuracy of judgment of facial expres... more The aim of the experiment was to study the relation between accuracy of judgment of facial expressions of emotions and time for judgment. The results for 34 college students confirmed previous data showing high performance in identification of all emotions, although there were some important differences between emotions. Also, times for judgment were longer for the emotions which were more difficult to identify.
The aim of this experiment was to study the identification of the facial expressions of six emoti... more The aim of this experiment was to study the identification of the facial expressions of six emotions in French-speaking québécois subjects. Two methods of stimuli presentation were used. The results showed high identification levels that were comparable to those of others working with various cultures. The simultaneous presentation of a facial expression and of the same face with a neutral expression had no effect on the subjects' accuracy of judgment. Female subjects had a higher identification level of disgust than male subjects. Finally, the analysis of the distribution of judgment errors partially confirmed previous data concerning confusions of emotions.
Monkeys with removals of medial temporal lobe (MTL) structures are widely recognized as valid mod... more Monkeys with removals of medial temporal lobe (MTL) structures are widely recognized as valid models of human global anterograde amnesia, a syndrome that arises consequent to damage to a finite set of brain structures situated in the medial temporal lobe and/or medial diencephalon. However, a comparison of memory deficits in human and nonhuman primates with MTL damage has presented a long-standing puzzle. Whereas amnesic patients are impaired in learning object discrimination problems, monkeys with MTL damage are typically not. One possible explanation for this difference is that object discrimination tasks for humans and monkeys differ in that the former but not the latter requires the use of contextual information. If this analysis is correct, monkeys with MTL damage might be disadvantaged in learning to discriminate similar objects presented in different contexts. To test this possibility, we evaluated the effects of excitotoxic lesions of one of the MTL structures, the hippocampus, on the rate of learning of discrimination problems embedded within unique contexts. Monkeys with hippocampal lesions were impaired relative to controls in learning object discrimination problems of this type. These findings strongly support the idea that the difference in the effect on object memory of MTL damage in human and nonhuman primates is due to a difference in the opportunity to employ contextual cues rather than to a difference in the organization of memory.
In the present experiment, sham-operated (SH) and fornix-transected (FX) rats were trained on a n... more In the present experiment, sham-operated (SH) and fornix-transected (FX) rats were trained on a new nonspatial, odor-guided task. On each session, eight odor pairs were presented twice. On the first occurrence of a pair, rats were reinforced for pushing the container (go response) in which the olfactory stimuli were placed. On the second occurrence, they were not reinforced and had to refrain from responding (no-go response) to be scored as success. Rats were first trained to criterion on odor pairs made of replicates of the same odor (S pairs). Then they were trained to criterion on pairs made of different odors, each member of the pair overlapping with that of another pair (O pairs) and finally, on pairs of different odors with no overlap (NO pairs). The results showed that the number of sessions to reach criterion was significantly higher in FX than in SH rats during training on O pairs, but not during training on S or on NO pairs. These findings are consistent with the configural (Rudy and Sutherland, 1995: Hippocampus 5:375-389) or relational (Eichenbaum et al., 1994: Behav Brain Sci 17:449-518) account of the hippocampal memory function.
The contribution of the dorsal subiculum (DS) and of the dorsal hippocampus (DH) to memory for di... more The contribution of the dorsal subiculum (DS) and of the dorsal hippocampus (DH) to memory for distinct and overlapping visual stimuli was examined. Rats with selective lesions of the DS or the DH were compared to sham-operated rats on a delayed matching-to-place task guided by distal visual cues in a modified radial-arm maze. Overlapping distal visual cues could be perceived from three arm entrances (adjacent arms) and a unique set of distal cues were more likely to be seen from the other two arm entrances (distinct arms). Rats with DS lesions were impaired on trials with baited adjacent arms, but not on trials with baited distinct arms. Rats with DH lesions were impaired on both types of trials. These results suggest that the DS and the DH are necessary for pattern separation and that they may have different contributions to memory.
As a preliminary step towards the use of natural odorants in laboratory imprinting studies, olfac... more As a preliminary step towards the use of natural odorants in laboratory imprinting studies, olfactory learning by young Atlantic salmon, Salmo salar, was assessed by heart rate conditioning to L-cysteine (3.8 × 10−4 M). Fish were successfully conditioned and decelerated their heart rate to L-cysteine compared with that of a control group tested under random pairing sequences of L-cysteine and an electrical stimulation. The cardiac conditioning response and sensitivity of fish to L-cysteine was unaffected by a procedure of curarization. Cardiac performance of fish conditioned to L-cysteine was also compared with that of other groups of fish exposed to four different odorous substances. The conditioned response increased significantly across trials when morpholine, L-cysteine, or L-phenylalanine was used as the conditioning stimulus, but remained unchanged throughout the experiment in the presence of L-serine or L-threonine.
Polymorphisms in the gene encoding the brain serotonin synthesis enzyme Tph2 have been identified... more Polymorphisms in the gene encoding the brain serotonin synthesis enzyme Tph2 have been identified in mental illnesses, with co-morbidity of substance use disorder. However, little is known about the impact of Tph2 gene variants on addiction. Mice expressing a human Tph2 loss of function variant were used to investigate consequences of aversive conditions on ethanol intake. Mice were familiarized either with ethanol or a solution containing both ethanol and the bittering agent quinine. Effect of familiarization to ethanol or an ethanol-quinine solution was then evaluated using a two-bottles preference test in Tph2-KI and control littermates. Mice from both genotypes displayed similar levels of ethanol consumption and quinine avoidance when habituated to ethanol alone. In contrast, addition of quinine to ethanol during the familiarization period resulted in a reduction of avoidance for the quinine-ethanol solution only in mutant mice. These results indicate that loss of function mutation in Tph2 results in greater motivation for ethanol consumption under aversive conditions and may confer enhanced sensitivity to alcohol use disorder.
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