Brain lesion and memory functioning: Short-term memory deficit is independent of lesion location

We analyzed the effects of patterns of brain lesions from penetrating head injuries on memory performance in participants of the Vietnam Head Injury Study (Grafman et al., 1988). Classes of lesion patterns were determined by mixture modeling (L. K. Muthén & B. O. Muthén, 1998-2004). Memory performance was assessed for short-term memory (STM), semantic memory, verbal episodic memory, and visual episodic memory. The striking finding was that large STM deficits were observed in all classes of brain-injured individuals, regardless of lesion location pattern. These effects persist despite frequent concomitant effects of depressive symptomatology and substance dependence. Smaller deficits in semantic memory, verbal episodic memory, and visual episodic memory depended on lesion location, in a manner roughly consistent with the existing neuropsychological literature. The theoretical and clinical implications of the striking, seemingly permanent STM deficits in individuals with penetrating head injuries are discussed.     

Beta-adrenergic receptor activation during distinct patterns of stimulation critically modulates the PKA-dependence of LTP in the mouse hippocampus

Activation of β-adrenergic receptors (β-ARs) enhances hippocampal memory consolidation and long-term potentiation (LTP), a likely mechanism for memory storage. One signaling pathway linked to β-AR activation is the cAMP-PKA pathway. PKA is critical for the consolidation of hippocampal long-term memory and for the expression of some forms of long-lasting hippocampal LTP. How does β-AR activation affect the PKA-dependence, and persistence, of LTP elicited by distinct stimulation frequencies? Here, we use in vitro electrophysiology to show that patterns of stimulation determine the temporal phase of LTP affected by β-AR activation. In addition, only specific patterns of stimulation recruit PKA-dependent LTP following β-AR activation. Impairments of PKA-dependent LTP maintenance generated by pharmacologic or genetic deficiency of PKA activity are also abolished by concurrent activation of β-ARs. Taken together, our data show that, depending on patterns of synaptic stimulation, activation of β-ARs can gate the PKA-dependence and persistence of synaptic plasticity. We suggest that this may allow neuromodulatory receptors to fine-tune neural information processing to meet the demands imposed by numerous synaptic activity profiles. This is a form of “metaplasticity” that could control the efficacy of consolidation of hippocampal long-term memories.The hippocampus importantly contributes to memory function in the mammalian brain (Zola-Morgan et al. 1986; Eichenbaum et al. 1990; Otto and Eichenbaum 1992; Phillips and LeDoux 1992; Remondes and Schuman 2004). It has reciprocal connections with numerous cortical areas, including those responsible for high-level integration of spatial and contextual data from the external environment (Lavenex and Amaral 2000). As such, the hippocampus is well positioned to receive and survey a broad range of information and select behaviorally salient data for long-term storage. Activity-dependent enhancement of hippocampal synaptic strength can store information carried in patterns of afferent neural activity (Bliss and Collingridge 1993; Moser et al. 1998; Nathe and Frank 2003; Whitlock et al. 2006). Substantial evidence suggests that long-term potentiation (LTP) of synaptic strength plays important roles in the formation of long-term memory (LTM) (Doyere and Laroche 1992; Bourtchuladze et al. 1994; Abel and Lattal 2001; Genoux et al. 2002). As such, mechanistic studies of LTP have shed valuable light on how the mammalian brain stores new information.The hippocampus receives dense noradrenergic projections from the locus coeruleus, a brain structure that can influence many vital brain functions, including attention, sleep, arousal, mood regulation, learning, and memory (Berridge and Waterhouse 2003). Both α- and β-adrenergic receptor subtypes are present on hippocampal neurons (Morrison and Foote 1986; Berridge and Waterhouse 2003), and noradrenaline (NA) acts on hippocampal β-adrenergic receptors (β-ARs) to facilitate the retention and recall of memory (Izquierdo et al. 1998; Ji et al. 2003; Murchison et al. 2004). In humans, stimulation of the noradrenergic neuromodulatory system enhances memory for emotional stimuli, and inhibition of β-ARs prevents this memory enhancement (Cahill et al. 1994; van Stegeren et al. 1998; O’Carroll et al. 1999).Consistent with the notion that selective enhancement of LTM may occur following β-AR activation, stimulation of β-ARs can also facilitate the persistence of LTP. In areas CA3 and CA1, β-AR activation facilitates the induction of long-lasting LTP when paired with certain patterns of electrical stimulation (Huang and Kandel 1996; Gelinas and Nguyen 2005). However, the mechanisms by which different patterns of stimulation control synaptic responsiveness to β-AR activation are unclear.β-ARs couple to guanine-nucleotide-binding regulatory Gs proteins to stimulate adenylyl cyclase activity and increase intracellular cAMP (Seeds and Gilman 1971; Maguire et al. 1977). A main target of cAMP signaling is activation of cAMP-dependent protein kinase (PKA), a kinase that is required for some forms of long-lasting LTP and for consolidation of hippocampal LTM (Frey et al. 1993; Abel et al. 1997; Nguyen and Woo 2003). Interestingly, the PKA-dependence of hippocampal LTP displays plasticity: Specific temporal patterns of synaptic stimulation, such as repeated and temporally spaced 100-Hz stimulation, elicit LTP that requires PKA for its expression (Woo et al. 2003). Also, spatial “enrichment” can increase the PKA-dependence of LTP in mice, and this is correlated with improved hippocampal memory function (Duffy et al. 2001). However, it is unclear whether activation of β-ARs can critically gate the PKA-dependence of LTP. In this study, we examine the effects of β-AR activation on LTP generated by various patterns of afferent stimulation in area CA1 of the hippocampus, and we determine the role of PKA in these β-AR-modulated forms of LTP.     

Noradrenergic activation of the basolateral amygdala modulates consolidation of object recognition memory

Noradrenergic activation of the basolateral complex of the amygdala (BLA) modulates the consolidation of memory for many kinds of highly emotionally arousing training tasks. The present experiments investigated whether posttraining noradrenergic activation of the BLA is sufficient to enable memory consolidation of a low-arousing training experience. Sprague-Dawley rats received intra-BLA infusions of norepinephrine, the beta-adrenoceptor antagonist propranolol or saline immediately after either 3 or 10 min of object recognition training. Saline-infused controls exhibited poor 24-h retention when given 3 min of object recognition training and good retention when given 10 min of training. Norepinephrine administered after 3 min of object recognition training produced dose-dependent enhancement of 24-h object recognition memory whereas propranolol administered after 10 min of training produced dose-dependent impairment of memory. These findings provide evidence that posttraining noradrenergic activation of the BLA enhances memory of a low-arousing training experience that would otherwise not induce long-term memory. Thus, regardless of the degree of emotional arousal induced by an experience, noradrenergic activation of the BLA after the experience ensures that it will be better remembered.     

Punishing Those Responsible for the Prison Abuses at Abu Ghraib: The Influence of the Negative Reciprocity Norm (NRN)

The negative reciprocity norm (NRN) is the personal moral code specifying retaliation as a proper response to wrongdoing ( Eisenberger, Lynch, Aselage, & Rohdieck, 2004 ). We examined the role of negative reciprocity in interpreting and reacting to the prison abuses at Abu Ghraib. Results showed that people who believed that American soldiers behaved wrongly at Abu Ghraib were more likely to view punishing the soldiers responsible as a highly moral response and were less likely to contribute money to a charitable organization that helps American soldiers. These relationships were only present among those highly endorsing the negative reciprocity norm.     

Computer speech-based remediation for reading disabilities: the size of spelling-to-sound unit in a transparent orthography

This study was designed to assess the effects of four reading-training procedures for children with reading disabilities (RD) in a transparent orthography, with the aim of examining the effects of different spelling-to-sound units in computer speech-based reading. We selected a sample of 83 Spanish children aged between 7 years 1 month and 10 years 6 months (M = 105.2, SD = 7.8) whose pseudoword reading performance was below the 25th percentile and IQ > 90. The participants were randomly assigned to five groups: (a) the whole-word training group (WW) (n = 17), (b) the syllable training group (S)(n = 16), (c) the onset-rime training group (OR) (n = 17), (d) the phoneme training group (P) (n = 15), and (e) the untrained control group (n = 18). Children were pre- and post-tested in word recognition, reading comprehension, phonological awareness, and orthographic and phonological tasks. The results indicate that experimental groups who participated in the phoneme and syllable conditions improved their word recognition in comparison with the control group. In addition, dyslexics who participated in the phoneme, syllable, and onset-rime conditions made a greater number of requests during computer-based word reading under conditions that required extensive phonological computation (low frequency words and long words). Reading time, however, was greater for long words in the phoneme group during computer-based reading. These results suggest the importance of training phonological processes in improving word decoding in children with dyslexia who learn in a consistent orthography.     

Flexible cue use in food-caching birds

An animal’s memory may be limited in capacity, which may result in competition among available memory cues. If such competition exists, natural selection may favor prioritization of different memory cues based on cue reliability and on associated differences in the environment and life history. Food-caching birds store numerous food items and appear to rely on memory to retrieve caches. Previous studies suggested that caching species should always prioritize spatial cues over non-spatial cues when both are available, because non-spatial cues may be unreliable in a changing environment; however, it remains unclear whether non-spatial cues should always be ignored when spatial cues are available. We tested whether mountain chickadees (Poecile gambeli), a food-caching species, prioritize memory for spatial cues over color cues when relocating previously found food in an associative learning task. In training trials, birds were exposed to food in a feeder where both spatial location and color were associated. During subsequent unrewarded test trials, color was dissociated from spatial location. Chickadees showed a significant pattern of inspecting feeders associated with correct color first, prior to visiting correct spatial locations. Our findings argue against the hypothesis that the memory of spatial cues should always take priority over any non-spatial cues, including color cues, in food-caching species, because in our experiment mountain chickadees chose color over spatial cues. Our results thus suggest that caching species may be more flexible in cue use than previously thought, possibly dependent upon the environment and complexity of available cues.     

The masculine role as a moderator of stress-distress relationships

Health psychologists often content that men are more vulnerable to the effects of stress than are women. One explanation of this male risk factor deals with the masculine role — the set of values, beliefs, and expectations traditionally associated with men's lives. The present study was conducted to determine whether the restrictive emotionality, success preoccupation, and inhibited affection aspects of the masculine role, measured by the Masculine Role Inventory [MRI; W. E. Snell, Jr., The Masculine Role Inventory (MRI): Components and Correlates, Rex Roles, 1986] increase not only men's but also women's vulnerability to the effects of stressful life experiences. The results indicated that among both men and women with a recent history of stressful experiences in their lives, the masculine role was associated with elevated distress.Portions of these data were presented at the 1985 annual meeting of the Southwestern Psychological Association, Austin, Texas.     

The masculine and feminine self-disclosure scale: The politics of masculine and feminine self-presentation

A self-disclosure questionnaire was devised to examine women's and men's willingness to disclose information about the masculine and feminine aspects of themselves. The Masculine and Feminine Self-Disclosure Scale (MFSDS) has four separate subscales: two masculine scales assess the tendency to discuss agentic, instrumental traits and behaviors; and two feminine scales measure the tendency to self-disclose about communal, expressive traits and behaviors. The results indicated that women's and men's disclosure of their masculine-instrumental and feminine-expressive traits and behaviors to a disclosure recipient was tempered by the content of the disclosure and the personal characteristics of the disclosure recipient. These findings were interpreted within a self-presentational analysis that women and men attempted to foster favorable masculine-instrumental and feminine-expressive images for particular persons.Portions of this research were presented at the annual meeting of the Southwestern Psychological Association, Dallas, Texas, April 1982. Gratitude is extended to Richard Archer for his helpful comments on an earlier version of this article.     

An objective evaluation of special class placement of elementary schoolboys with behavior problems

Behavioral checklists were employed to identify the type and degree of psychopathology observed in 90 boys who were referred for possible placement in classrooms for the socially and emotionally disturbed (SED). School behavior was assessed by teachers completing the Conners Teacher Rating Scale, while behavior at home was rated by parents with the Child Behavior Checklist. The checklist findings from both environments showed the boys to have high levels of psychological disturbance, especially for externalizing factors such as hyperactivity, aggression, and conduct disorder. This was especially true for those boys for whom SED placement was recommended. Further, the clinical usefulness of these checklists was investigated as an adjunctive method for the determination of the need for SED placement. By the use of discriminant function analysis, about three-fourths of the boys recommended for SED placement were accurately identified; correct classification was maximized when parent and teacher checklists were employed together.     

Profiling desired state type problem recognizers

Style of recognizing consumer problems has been identified in past research as a unique variable for effectively segmenting a market based upon potential purchase behavior. However, only one product category has been examined in previous studies thereby limiting the generalizability of the results. The present study examined shopping orientation and demographic characteristics of problem recognizers for six different product categories, with special attention devoted to Desired State Type Problem Recognizers. Profiles developed for these Desired State Type consumers were significantly different from Actual State Types for each of the six products. Some limited commonality was found for Desired State Types across five of the six product categories.