Posterior parietal cortex and episodic retrieval: Convergent and divergent effects of attention and memory

Functional neuroimaging studies of humans engaged in retrieval from episodic memory have revealed a surprisingly consistent pattern of retrieval-related activity in lateral posterior parietal cortex (PPC). Given the well-established role of lateral PPC in subserving goal-directed and reflexive attention, it has been hypothesized that PPC activation during retrieval reflects the recruitment of parietal attention mechanisms during remembering. Here, we evaluate this hypothesis by considering the anatomical overlap of retrieval and attention effects in lateral PPC. We begin by briefly reviewing the literature implicating dorsal PPC in goal-directed attention and ventral PPC in reflexive attention. We then discuss the pattern of dorsal and ventral PPC activation during episodic retrieval, and conclude with consideration of the degree of anatomical convergence across the two domains. This assessment revealed that predominantly divergent subregions of lateral PPC are engaged during acts of episodic retrieval and during goal-directed and reflexive attention, suggesting that PPC retrieval effects reflect functionally distinct mechanisms from these forms of attention. Although attention must play a role in aspects of retrieval, the data reviewed here suggest that further investigation into the relationship between processes of attention and memory, as well as alternative accounts of PPC contributions to retrieval, is warranted.Episodic memory—declarative memory for events—has long been known to depend on the medial temporal lobe and, to a lesser extent, the prefrontal cortex (Squire 1992; Shimamura 1995; Wheeler et al. 1995; Gabrieli 1998; Eichenbaum and Cohen 2001; Squire et al. 2004). Recently, an explosion of functional neuroimaging studies has revealed that episodic retrieval is also consistently associated with activity in lateral posterior parietal cortex (PPC), including in the intraparietal sulcus and inferior parietal lobule (Figs. 1, ​,2;2; for detailed review, see Wagner et al. 2005; Cabeza 2008; Cabeza et al. 2008; Ciaramelli et al. 2008; Vilberg and Rugg 2008b; Olson and Berryhill 2009). This unexpected finding raises the possibility that parietal mechanisms may be more central to episodic retrieval than previously thought.Open in a separate windowFigure 1.Anatomy of posterior parietal cortex (PPC). A posterior-lateral view of human PPC is depicted, with PPC separated into dorsal and ventral portions by the intraparietal sulcus (IPS). Dorsal PPC includes the superior parietal lobule (SPL) and IPS. Ventral PPC includes inferior parietal lobule (IPL) and its subregions: supramarginal gyrus (SMG), temporoparietal junction (TPJ), and angular gyrus (AnG).Open in a separate windowFigure 2.Left lateral PPC activity during episodic retrieval. (A) A comparison of hits relative to correct rejections reported by Kahn et al. (2004) revealed “old/new” effects in dorsal PPC, inclusive of IPS. Average signal change within IPS was greater for items perceived as old (hits and false alarms) vs. those believed to be new (misses and correct rejections). (B) A comparison of successful, relative to unsuccessful, cued recall by Kuhl et al. (2007) revealed greater activity in AnG, compatible with the broader literature on recollection success effects (see Fig. 4). In addition, effects were observed in more anterior aspects of ventral PPC (SMG), as well as in dorsal PPC (principally SPL) (see Discussion). (C) Orienting to memory in attempts to recollect, independent of recollection success, is often associated with activity in dorsal PPC. For example, comparison of temporal recency judgments to novelty-based decisions elicited greater IPS activity (Dudukovic and Wagner 2007).At the neuropsychological level, human lesion evidence regarding the necessity of lateral PPC mechanisms for episodic retrieval is limited and mixed (Berryhill et al. 2007; Davidson et al. 2008; Haramati et al. 2008; Simons et al. 2008). By contrast, other neuropsychological data indicate that lateral PPC is unambiguously associated with another cognitive domain—attention (Posner et al. 1984; Mesulam 1999; Parton et al. 2004). This latter lesion literature is further complemented by rich functional neuroimaging evidence implicating dorsal and ventral PPC in goal-directed and reflexive attention, respectively (for review, see Corbetta and Shulman 2002; Corbetta et al. 2008).Drawing from the rich literature linking attention to lateral PPC, memory researchers have recently proposed that lateral PPC activity during episodic retrieval tasks reflects the engagement of attention mechanisms during remembering (Cabeza 2008; Cabeza et al. 2008; Ciaramelli et al. 2008; Olson and Berryhill 2009). Specifically, it has been hypothesized that: (1) Dorsal PPC activity during retrieval may reflect the recruitment of goal-directed attention in service of performing retrieval tasks and (2) ventral PPC engagement during retrieval may mark the reflexive capture of attention by mnemonic representations. While prior comprehensive reviews of the neuroimaging literature on parietal correlates of episodic retrieval have documented functional dissociations along the dorsal/ventral axis of lateral PPC, which qualitatively parallel those seen in the attention literature, evaluation of the hypothesis that PPC retrieval activity reflects attention mechanisms further requires an assessment of the degree to which attention and retrieval effects co-localize. Here we review lateral PPC correlates of both episodic retrieval and attention, with the goal of directly assessing to the degree of anatomic overlap.It should be noted from the outset that the aim of the present review is to evaluate the hypothesis that lateral PPC episodic retrieval effects can be explained in terms of goal-directed and reflexive attention mechanisms. As such, we a priori imposed three constraints that served to focus our treatment of these two substantial literatures. First, while both the dual-attention and memory retrieval literatures focus on effects on the lateral parietal surface, retrieval effects are predominantly left lateralized. Thus, we constrained our analysis of attention and retrieval findings to left lateral PPC.⁵ Second, because prior retrieval reviews focused theoretical discussion on dual-attention accounts, here we similarly constrained our treatment of the extensive attention literature to include only those effects relevant to dual-attention theory. Finally, because the preponderance of evidence offered in support of dual-attention theory''s proposed dorsal attention network derives from studies of visual attention, the present review of the dorsal network is also confined to visual attention. As such, the present review should not be viewed as a comprehensive review of the entire attention literature.We first survey the functional neuroimaging literature on parietal correlates of goal-directed and reflexive attention, and then discuss how these correlates converge and diverge with the patterns of lateral PPC activity present during episodic retrieval. We conclude by considering theoretical frameworks that focus on the role of attention in episodic retrieval, as well as nonattention-based accounts of PPC activity during retrieval, and we highlight open questions that await further investigation.     

EFFECTS OF RESPONSE SPACING ON ACQUISITION AND RETENTION OF CONDITIONAL DISCRIMINATIONS

Pigeons were exposed to a repeated acquisition procedure in which no delays were imposed and rate of responding was relatively high. They also were exposed to conditions in which delays were arranged between trials within chains or between completed chains, and rates of responding were lower. Number of trials, rate of reinforcement, difficulty of the discrimination, and motivating operations were held constant. Terminal accuracy was highest under the no‐delay condition, in which rate of responding was highest. Effects of trial spacing on retention were mixed and depended on whether delays were imposed between trials within chains or between completed chains. These findings provide basic‐research support for the rapid presentation of trials in direct instruction and for rate building in precision teaching.     

Embodied communication: Speakers’ gestures affect listeners’ actions

We explored how speakers and listeners use hand gestures as a source of perceptual-motor information during naturalistic communication. After solving the Tower of Hanoi task either with real objects or on a computer, speakers explained the task to listeners. Speakers’ hand gestures, but not their speech, reflected properties of the particular objects and the actions that they had previously used to solve the task. Speakers who solved the problem with real objects used more grasping handshapes and produced more curved trajectories during the explanation. Listeners who observed explanations from speakers who had previously solved the problem with real objects subsequently treated computer objects more like real objects; their mouse trajectories revealed that they lifted the objects in conjunction with moving them sideways, and this behavior was related to the particular gestures that were observed. These findings demonstrate that hand gestures are a reliable source of perceptual-motor information during human communication.     

Doing gender differently—The interplay of strength of gender identification and content of gender identity in predicting women's endorsement of sexist beliefs

To explain differences in women's endorsement of sexist beliefs, we introduce the gender identity model (GIM). Based on social identity theory (SIT) and social role theory (SRT), we combine strength of gender identification and identity content and propose that different types of gender identity can be distinguished, which are predicted to relate to different levels of women's endorsement of sexist beliefs and engagement in collective action. Results of a correlational study and two experiments support the assumptions of the model: women reject Benevolent (BS), Hostile (HS), and Modern Sexisms (MS) and participate in collective action in particular when they are highly identified with the category women and have, at the same time, internalized progressive identity contents. In contrast, gender role preference has weaker or no effects on sexist beliefs and collective action when women are low identified with their gender in‐group. Copyright © 2008 John Wiley & Sons, Ltd.     

Attention during memory retrieval enhances future remembering

Memory retrieval is a powerful learning event that influences whether an experience will be remembered in the future. Although retrieval can succeed in the presence of distraction, dividing attention during retrieval may reduce the power of remembering as an encoding event. In the present experiments, participants studied pictures of objects under full attention and then engaged in item recognition and source memory retrieval under full or divided attention. Two days later, a second recognition and source recollection test assessed the impact of attention during initial retrieval on long-term retention. On this latter test, performance was superior for items that had been tested initially under full versus divided attention. More importantly, even when items were correctly recognized on the first test, divided attention reduced the likelihood of subsequent recognition on the second test. The same held true for source recollection. Additionally, foils presented during the first test were also less likely to be later recognized if they had been encountered initially under divided attention. These findings demonstrate that attentive retrieval is critical for learning through remembering.     

Ausbildungs- und Berufserfahrungen älterer Psychoanalytiker

Based on the discussion about the crisis of psychoanalysis and in particular of psychoanalytic training, 145 (female and male) analysts older than 70 years of age were interviewed about their training and professional experiences as well as about their attitudes towards psychoanalysis. This older generation is of great interest because their training generally took place prior to 1967 and preceded the introduction of guideline therapy (cost coverage by the general health insurance) and under much less formalized conditions, which can be seen almost as a contrast to the current circumstances and conditions. This research has shown that especially personal or content and value-based motivations (personal problems, therapeutic experience, interest in the subject, the desire for depth, self-realization and expansion of the situation perceived as restrictive of their former profession) were the main determining factors for the choice of career. The training analyses were, despite some exceptions, of substantial length even then (an average of 544 h), but often had a lower frequency (30% had less than 3 h per week). Since the age limitation for running a psychoanalytic practice within the general health services (formerly 68 years) is no longer compulsory, the results of this study regarding the professional life of older psychoanalysts are of special interest. Of the respondents 45% are still running their own practice and 22% are working as training analysts.     

Target-biting behavior of individually and group-housed mice and rats

The effects of housing conditions (individual or grouped) on the biting of an inanimate target by confined male mice and rats were measured. It was observed that, for both mice and rats, individual housing markedly increased the number of target bites per session. These results indicate that the target-biting paradigm is sensitive to those factors responsible for the increase in fighting behavior following individual housing.     

How human abilities affect component skills in word processing

Even simple tasks such as basic word processing can be quite complex. This paper argues that such tasks can be decomposed into a set of component skills and suggests how user abilities affect performance based on those skills. Special attention is given to spatial memory tests. It is argued that these tests actually assess two separable abilities: visual search and retention of order information. Skill acquisition can be facilitated by taking these abilities into account in system design: The importance of searching is decreased by providing context searches in which the system locates items in a text, and the importance of remembering the order of command sequences is improved by decreasing procedural complexity.