Fear and the human amygdala

We have previously reported that bilateral amygdala damage in humans compromises the recognition of fear in facial expressions while leaving intact recognition of face identity (Adolphs et al., 1994). The present study aims at examining questions motivated by this finding. We addressed the possibility that unilateral amygdala damage might be sufficient to impair recognition of emotional expressions. We also obtained further data on our subject with bilateral amygdala damage, in order to elucidate possible mechanisms that could account for the impaired recognition of expressions of fear. The results show that bilateral, but not unilateral, damage to the human amygdala impairs the processing of fearful facial expressions. This impairment appears to result from an insensitivity to the intensity of fear expressed by faces. We also confirmed a double dissociation between the recognition of facial expressions of fear, and the recognition of identity of a face: these two processes can be impaired independently, lending support to the idea that they are subserved in part by anatomically separate neural systems. Based on our data, and on what is known about the amygdala's connectivity, we propose that the amygdala is required to link visual representations of facial expressions, on the one hand, with representations that constitute the concept of fear, on the other. Preliminary data suggest the amygdala's role extends to both recognition and recall of fearful facial expressions

Exploring the concept of homeostasis and considering its implications for economics

AbstractIn its standard format, the concept of homeostasis refers to the ability, present in all living organisms, of continuously maintaining certain functional variables within a range of values compatible with survival. The mechanisms of homeostasis were originally conceived as strictly automatic and as pertaining only to the state of an organism's internal environment. In keeping with this concept, homeostasis was, and still is, often explained by analogy to a thermostat: upon reaching a previously set temperature, the device commands itself to either suspend the ongoing operation (cooling or heating), or to initiate it, as appropriate. This traditional explanation fails to capture the richness of the concept and the range of circumstances in which it can be applied to living systems. Our goal here is to consider a more comprehensive view of homeostasis. This includes its application to systems in which the presence of conscious and deliberative minds, individually and in social groups, permits the creation of supplementary regulatory mechanisms aimed at achieving balanced and thus survivable life states but more prone to failure than the fully automated mechanisms. We suggest that an economy is an example of one such regulatory mechanism, and that facts regarding human homeostasis may be of value in the study of economic problems. Importantly, the reality of human homeostasis expands the views on preferences and rational choice that are part of traditionally conceived Homo economicus and casts doubts on economic models that depend only on an “invisible hand” mechanism

Pain and other feelings in humans and animals

Evidence from neuroanatomy, neurophysiology, and neuropsychology suggests that the experience of feelings in humans does not depend exclusively on structures of the cerebral cortex. It does not seem warranted to deny the possibility of feeling in animals on the grounds that their cerebral cortices are not comparable to those of humans

Sensing is a far cry from sentience

The hypothesis that plants might be sentient confuses the notion of sentience (or consciousness) with that of sensing. Sentience/consciousness implies feeling, experience, and subjectivity. Sensing does not. Plants can sense/detect and even respond appropriately in the absence of any sentience/consciousness

O Gnuteca e o OpenBiblio: avaliação de softwares livres para a automação de bibliotecas

Leaving of the necessity of users of university libraries, currently working in more digital and available platforms each time in the Internet, free softwares has versions searching to answer adequately to these demands, being sold at a loss general costs of implantation of software. The present article aims at to carry through the comparative evaluation between two softwares free: the OpenBiblio and the Gnuteca, amongst other available ones in the Brazilian market of softwares for university libraries while complete systems of automation. A revision of national and international literature was made, having as methodology the important considered election of itens in this task. The choice of a software (either of “free code” or proprietor) that it works as automatized systems covering all its functions of university libraries, requires to consider aspects as so great of quantities, strategies of growth, human resources and financial e, over all, the demands of its users varying very of library for library. We point, for end, general aspects of the comparative evaluation between the OpenBiblio and the Gnuteca and of the evaluated criteria

Fear and the human amygdala

We have previously reported that bilateral amygdala damage in humans compromises the recognition of fear in facial expressions while leaving intact recognition of face identity (Adolphs et al., 1994). The present study aims at examining questions motivated by this finding. We addressed the possibility that unilateral amygdala damage might be sufficient to impair recognition of emotional expressions. We also obtained further data on our subject with bilateral amygdala damage, in order to elucidate possible mechanisms that could account for the impaired recognition of expressions of fear. The results show that bilateral, but not unilateral, damage to the human amygdala impairs the processing of fearful facial expressions. This impairment appears to result from an insensitivity to the intensity of fear expressed by faces. We also confirmed a double dissociation between the recognition of facial expressions of fear, and the recognition of identity of a face: these two processes can be impaired independently, lending support to the idea that they are subserved in part by anatomically separate neural systems. Based on our data, and on what is known about the amygdala's connectivity, we propose that the amygdala is required to link visual representations of facial expressions, on the one hand, with representations that constitute the concept of fear, on the other. Preliminary data suggest the amygdala's role extends to both recognition and recall of fearful facial expressions

Damage to Ventromedial Prefrontal Cortex Impairs Judgment of Harmful Intent

SummaryMoral judgments, whether delivered in ordinary experience or in the courtroom, depend on our ability to infer intentions. We forgive unintentional or accidental harms and condemn failed attempts to harm. Prior work demonstrates that patients with damage to the ventromedial prefrontal cortex (VMPC) deliver abnormal judgments in response to moral dilemmas and that these patients are especially impaired in triggering emotional responses to inferred or abstract events (e.g., intentions), as opposed to real or actual outcomes. We therefore predicted that VMPC patients would deliver abnormal moral judgments of harmful intentions in the absence of harmful outcomes, as in failed attempts to harm. This prediction was confirmed in the current study: VMPC patients judged attempted harms, including attempted murder, as more morally permissible relative to controls. These results highlight the critical role of the VMPC in processing harmful intent for moral judgment

The Human Amygdala and the Induction and Experience of Fear

Although clinical observations suggest that humans with amygdala damage have abnormal fear reactions and a reduced experience of fear [1-3], these impressions have not been systematically investigated. To address this gap, we conducted a new study in a rare human patient, SM, who has focal bilateral amygdala lesions [4]. To provoke fear in SM, we exposed her to live snakes and spiders, took her on a tour of a haunted house, and showed her emotionally evocative films. On no occasion did SM exhibit fear, and she never endorsed feeling more than minimal levels of fear. Likewise, across a large battery of self-report questionnaires, 3 months of real-life experience sampling, and a life history replete with traumatic events, SM repeatedly demonstrated an absence of overt fear manifestations and an overall impoverished experience of fear. Despite her lack of fear, SM is able to exhibit other basic emotions and experience the respective feelings. The findings support the conclusion that the human amygdala plays a pivotal role in triggering a state of fear and that the absence of such a state precludes the experience of fear itself

A role for left temporal pole in the retrieval of words for unique entities

r r Abstract: Both lesion and functional imaging studies have implicated sectors of high-order association cortices of the left temporal lobe in the retrieval of words for objects belonging to varied conceptual categories. In particular, the cortices located in the left temporal pole have been associated with naming unique persons from faces. Because this neuroanatomical-behavioral association might be related to either the specificity of the task (retrieving a name at unique level) or to the possible preferential processing of faces by anterior temporal cortices, we performed a PET imaging experiment to test the hypothesis that the effect is related to the specificity of the word retrieval task. Normal subjects were asked to name at unique level entities from two conceptual categories: famous landmarks and famous faces. In support of the hypothesis, naming entities in both categories was associated with increases in activity in the left temporal pole. No main effect of category (faces vs. landmarks/buildings) or interaction of task and category was found in the left temporal pole. Retrieving names for unique persons and for names for unique landmarks activate the same brain region. These findings are consistent with the notion that activity in the left temporal pole is linked to the level of specificity of word retrieval rather than the conceptual class to which the stimulus belongs. Hum. Brain Mapping 13:199–212, 2001. © 2001 Wiley-Liss, Inc. Key words: left temporal pole; language; word retrieval; functional imaging; face processing; naming r