Greater dependence on working memory and restricted familiarity in orangutans compared with rhesus monkeys

The prefrontal cortex is larger than would be predicted by body size or visual cortex volume in great apes compared with monkeys. Because prefrontal cortex is critical for working memory, we hypothesized that recognition memory tests would engage working memory in orangutans more robustly than in rhesus monkeys. In contrast to working memory, the familiarity response that results from repetition of an image is less cognitively taxing and has been associated with nonfrontal brain regions. Across three experiments, we observed a striking species difference in the control of behavior by these two types of memory. First, we found that recognition memory performance in orangutans was controlled by working memory under conditions in which this memory system plays little role in rhesus monkeys. Second, we found that unlike the case in monkeys, familiarity was not involved in recognition memory performance in orangutans, shown by differences with monkeys across three different measures. Memory in orangutans was not improved by use of novel images, was always impaired by a concurrent cognitive load, and orangutans did not accurately identify images seen minutes ago. These results are surprising and puzzling, but do support the view that prefrontal expansion in great apes favored working memory. At least in orangutans, increased dependence on working memory may come at a cost in terms of the availability of familiarity.

The prefrontal cortex is critical for a suite of cognitive control processes that are conspicuous in human cognition (Miller 2000; Rougier et al. 2005; Braver et al. 2009). One such process is working memory, which actively maintains representations in a state of heightened access for further processing (Baddeley and Hitch 1974; Engle 2010). Working memory and cognitive control are positively correlated with measures of general intelligence in humans, implicating the prefrontal cortex as a key neural structure in the evolution of human cognition (Gray et al. 2003; Unsworth and Engle 2007; Cole et al. 2012). Some neuroanatomical studies have found that the prefrontal cortex is larger than would be predicted based on body size and visual cortex volume in apes compared with monkeys (Rilling 2006; Passingham and Smaers 2014). These findings suggest that the prefrontal cortex expanded disproportionately in great apes during primate evolution. Disproportionate expansion of the prefrontal cortex in great apes may have resulted in greater capacity for cognitive control functions, such as working memory, compared with monkeys. Thus, studies directly comparing working memory in monkeys and apes are critical to understanding the evolution of intelligence in primates.The role of cognitive control, and thus the prefrontal cortex, varies among memory systems. For instance, working memory relies heavily on cognitive control, consuming substantial cognitive resources, and is known to depend on frontal brain areas (Goldman-Rakic 1995; Fuster 1997). In contrast, familiarity, which is a strength-based memory signal that codes for whether or not a percept has previously been experienced (Kelley and Jacoby 1998; Yonelinas 2002), relies substantially less on cognitive control, consumes fewer cognitive resources, and has been mostly associated with nonfrontal areas of the brain such as the perirhinal cortex (Bachevalier and Mishkin 1986; Brown and Aggleton 2001; Haskins et al. 2008; Tu et al. 2011; O''Neil et al. 2012). Thus, working memory and familiarity vary in the degree to which they rely on cognitive control, and the degree to which they rely on prefrontal areas of the brain.If a relatively large prefrontal cortex enhances cognitive control and working memory, then we should expect recognition memory tests to engage working memory relatively more in apes than in monkeys. We evaluated this hypothesis by comparing the contributions of working memory and familiarity with recognition memory performance in orangutans and rhesus monkeys. Because the orangutans and monkeys here compared have different experience with cognitive testing, we aimed to compare the relative contributions of working memory and familiarity in each species, rather than the absolute accuracy of the two species in a particular memory test. This follows a logic similar to that used in many comparative anatomical studies; for example, those cited here that found the prefrontal cortex is larger in apes relative to body weight or visual cortex volume, rather than simply absolute volume.The relative contributions of working memory and familiarity to behavior can be measured in visual recognition memory tests. In these tests subjects study a sample image at the beginning of each trial and after a delay they are presented with a test consisting of the recently seen sample image among distractors (Fig. 1). The images used in these tests can either be repeated, such that the subject''s job is to determine which image in a set of familiar images was seen most recently, or the images can be trial unique, such that at test subjects need to discriminate a previously seen image from novel distractors. Working memory is critical for solving tests with repeating images, but much less so for tests using trial unique images, where familiarity plays a much greater role (Brady and Hampton 2018a). Monkeys (Jitsumori et al. 1988; Basile and Hampton 2013a) and apes (Harlow 1944; Hayes and Thompson 1953) are more accurate and better tolerate long delay intervals in tests with trial-unique stimuli, when familiarity can support performance. Experimentally naïve monkeys require comparatively little training to demonstrate proficient use of familiarity as a mnemonic cue, compared with the training required to become proficient in using working memory (Mishkin and Delacour 1975). Active working memory and passive familiarity are independent mnemonic processes that can be doubly dissociated. Working memory is impaired by a concurrent cognitive load imposed during the memory interval, while familiarity is not affected (Logie 1986; Jacoby et al. 1989; Basile and Hampton 2013a; Brady and Hampton 2018a). Completing the double dissociation, equating the familiarity of the sample and distractor images during study impairs choice based on familiarity, but not working memory (Brady and Hampton 2018a). Thus, recognition memory tests may allow us to compare the relative contributions of these two memory processes with recognition performance across species.Open in a separate windowFigure 1.Recognition memory tests with repeating and trial-unique images. (A) In tests with trial-unique images, each image was only used once as a sample or a distractor within a session. (B) When tested with repeating images, the images were the same on each trial. The sample image was pseudorandomly selected each trial such that each image appeared equally often as the sample or as a distractor.One might expect orangutans to show greater dependence on working memory compared with rhesus monkeys for at least two reasons. First, working memory is highly refined in humans and orangutans are more closely related to humans phylogenetically, sharing a common ancestor 13 million to 14 million years ago (Stewart and Disotell 1998), whereas rhesus monkeys and humans shared a common ancestor ∼32 million years ago (Roos and Zinner 2015). Second, orangutans have a relatively larger prefrontal cortex compared with monkeys (Rilling 2006; Passingham and Smaers 2014). We compared the ability of rhesus monkeys and orangutans to maintain images from different sets in working memory. We also determined the extent to which familiarity contributed to recognition memory performance. Across three experiments, we observed striking species differences. We found that in orangutans, recognition memory performance for both repeating and trial-unique images was controlled by working memory. In contrast, monkeys relied on working memory for repeating images, and on familiarity for trial-unique images. Furthermore, monkeys dramatically outperformed orangutans in tests that exceeded the capacity and duration of working memory, and thus depended on familiarity.     

Are individual differences in appetitive and defensive motivation related? A psychophysiological examination in two samples

Appetitive and defensive motivation account for a good deal of variance in personality and mental health, but whether individual differences in these systems are correlated or orthogonal has not been conclusively established. Previous investigations have generally relied on self-report and have yielded conflicting results. We therefore assessed the relation between psychophysiological indices of appetitive and defensive motivation during elicitation of these motivational states: specifically, frontal electroencephalogram asymmetry during reward anticipation and startle response during anticipation of predictable or unpredictable threat of shock. Results in a sample of psychopathology-free community members (n=63), an independent sample of undergraduates with a range of internalising symptoms (n=64), and the combination of these samples (n=127) revealed that differences in responding to the two tasks were not significantly correlated. Average coefficients approached zero in all three samples (community: .04, undergraduate: ?.01, combined: .06). Implications of these findings for research on normal and abnormal personality are discussed.     

J. M. Keynes's position on the general applicability of mathematical,logical and statistical methods in economics and social science

The author finds no support for the claim that J. M. Keynes had severe reservations, in general, as opposed to particular, concerning the application of mathematical, logical and statistical methods in economics. These misinterpretations rest on the omission of important source material as well as a severe misconstrual ofThe Treatise on Probability (1921).The author acknowledges substantial help from Jaakko Hintikka, but is necessarily responsible for any shortcomings.     

What teacher factors influence their attributions for children's difficulties in learning?

Background Identifying the factors that influence teacher beliefs about teaching children with learning difficulties is important for the success of inclusive education. This study explores the relationship between teachers' role, self‐efficacy, attitudes towards disabled people, teaching experience and training, on teachers' attributions for children's difficulties in learning. Method One hundred and eighteen primary school teachers (44 general mainstream, 33 mainstream learning support, and 41 special education teachers) completed the short form of the Teachers' Sense of Efficacy Scale, the Interaction with Disabled Persons Scale (IDP), and a revised version of the Teacher Attribution Scale. Results Regression analysis found that teachers' role influenced stability and controllability attributions. However, for stability attributions the effect was not sustained when examined in the context of the other factors of teaching efficacy, experience, training, and attitudes towards disability. What emerged as important instead was strong feelings of sympathy towards disabled people which predicted stable attributions about learning difficulties. Experience of teaching children with additional support needs and teaching efficacy positively predicted external locus of causality attributions. Surprisingly, training was not found to have an impact on attributions. A mixed MANOVA found that mainstream teachers' controllability attributions were influenced by whether or not the child had identified learning support needs. Conclusions Teacher efficacy, experience of teaching students with support needs, attitudes towards disabled people, and teachers' role all impact on teacher attributions, but no relationship with training was found. Implications for teacher training and development, and for student achievement and student self‐perception are discussed.     

A Web-Based Contingency Management Program With Adolescent Smokers

The present study evaluated a new 30-day Web-based contingency management program for smoking abstinence with 4 daily-smoking adolescents. Participants made 3 daily video recordings of themselves giving breath carbon monoxide (CO) samples at home that were sent electronically to study personnel. Using a reversal design, participants could earn money for continued abstinence during the treatment phases (CO ≤ 5 ppm). All participants were compliant with the treatment (submitting 97.2% of samples), and all achieved prolonged abstinence from smoking.     

Adaptive Coping Reduces the Impact of Community Violence Exposure on Violent Behavior among African American and Latino Male Adolescents

This study examined whether coping moderated the impact of community violence exposure (CVE) on violent behavior among 285 urban African American and Latino adolescent males assessed annually across 5 years. Composites indicating overall CVE (having knowledge of others’ victimization, witnessing violence, direct victimization) and approach to coping with CVE were created by averaging across years 1–3 (Time 1; mean ages 14–16). Adolescents classified as coping effectively tended to respond to CVE in beneficial ways (e.g., developing long-term solutions, engaging in positive reappraisal). Violent behavior was examined across years 1–3 (Time 1) and years 4–5 (Time 2; mean ages 18–19). CVE was longitudinally associated with greater violent behavior, adjusting for Time 1 levels of violent behavior. This association was significant only among adolescents with less effective coping strategies. Interventions targeting the enhancement of coping skills may be an effective method of reducing the impact of CVE on adolescent violent behavior. Sonya S. Brady is now an Assistant Professor in the Division of Epidemiology and Community Health, School of Public Health at the University of Minnesota (1300 South Second Street, Suite 300, Minneapolis, MN 55454-1015, USA; Tel.: +1-612-6241818; Fax: +1-612-6240315.     

Some Worries about Normative and Metaethical Sentimentalism

In this response I raise a number of problems for Michael Slote's normative and metaethical sentimentalism. The first is that his agent–based account of rightness needs be qualified in order to be plausible; any such qualification, however, leaves Slote's normative ethics in tension with his metaethical views. The second is that an agent–based ethics of empathic caring will indeed struggle to capture our common–sense understanding of deontological constraints, and that appeal to the notion of causal immediacy will be of little help here. Finally, it seems to me that Slote's metaethical account will turn out to be much less externalist (and hence, by his own lights, much less plausible) than he suspects.     

Neuropsychological profile following suicide attempt by hanging: two adolescent case reports.

Hippocampal damage and amnesia following hypoxia and ischemia are described in the few published adult cases of suicide attempt by hanging. However, a recent review (Caine & Watson, 2000) suggests a variable pattern of brain involvement and neuropsychological impairments following hypoxic-ischemic injury that may or may not involve amnesia. To help clarify the impact of hanging on the developing brain, we examined neuropsychological functioning in two adolescents who survived suicide attempt by hanging. Despite differences in Glasgow Coma Scale (GCS), coma duration, and structural imaging findings, both patients had similar IQ (VIQ>PIQ) and presented with various combinations of deficits in expressive/receptive language, visual-constructional and perceptual ability, processing speed, attention, working memory, and/or executive functioning shortly after injury. In spite of their similarities, only one of the patients presented with classic amnesia symptoms in his early recovery. This patient was evaluated 1 year postinjury, and persistent deficits in processing speed and memory encoding were noted. Several hanging-related variables, including longer estimated hanging duration, greater weight, and severe airway edema, were thought to place this patient at increased risk for cognitive deficits. Clinical MRI scans of this patient obtained 6 weeks postinjury revealed mild volume loss as well as abnormalities in bilateral superior cortex. However, CT and MRI scans obtained throughout early recovery did not reveal overt evidence of injury to specific memory-related structures. Comprehensive neuropsychological evaluation of all adolescent survivors of suicide attempt by hanging is recommended, as a variety of postacute cognitive deficits were observed in these patients despite relatively short (相似文献