Cognitive contributions of the ventral parietal cortex: an integrative theoretical account

Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive operations specific to each domain. In this article, we propose a hypothesis that can account for VPC activations across all the cognitive domains reviewed. We first review VPC activations in the domains of perceptual and motor reorienting, episodic memory retrieval, language and number processing, theory of mind, and episodic memory encoding. Then, we consider the localization of VPC activations across domains and conclude that they are largely overlapping with some differences around the edges. Finally, we assess how well four different hypotheses of VPC function can explain findings in various domains and conclude that a bottom-up attention hypothesis provides the most complete and parsimonious account.     

Controlling lexical contributions to the reading of pseudohomophones

Reynolds and Besner (2005) presented a computational account of six effects that emerge when readers are asked to pronounce pseudohomophones (nonwords—e.g., brane—that sound like words when pronounced). In the dual route cascaded (DRC) model of reading, they varied a parameter controlling the rate of inhibition from letter units to the orthographic lexicon to mimic strategic control over the extent of specific lexical processing. In this article, we provide an account in which the effects are simulated by varying the DRC’s reading-aloud criterion—a parameter that sets the minimal level of phonemic activation required to pronounce a letter string. We show that varying this parameter provides another means of controlling lexical contributions to reading aloud.     

Audience surveillance and the right to anonymous reading in interactive media

The proliferation of interactive media has provided corporations with an unprecedented ability to collect information about individuals’ media consumption habits. This ability of corporations is often reinforced by the rhetoric of “consumer sovereignty,” whereby individuals are misled into entrusting a considerable amount of information about their daily activities in exchange for increased convenience. The purpose of this paper is to explain the ways in which the information that individuals reveal to content and technology providers is subject to the scrutiny of external constituencies. More importantly, this paper, through an analysis of legal precedents, will demonstrate that the right to read anonymously is an important corollary of freedom of speech and that the ability of corporations to share information about individuals’ media consumption habits threatens this right. His research interests include privacy, digital rights management systems, and tensions that exist between privacy rights of individuals and intellectual property. An earlier version of this article was presented at the America: Visions and Divisions Conference, Austin 2003. The author would like to thank Oscar H. Gandy and Daniel P. Hillyard for his close reading of this article and helpful suggestions.     

Working memory contributions to reading comprehension components in middle childhood children

This study examined working memory contributions to reading comprehension subskills in Greek children (mean age 9 years, 1 month). The phonological loop of the Baddeley and Hitch working memory model was assessed with 3 recall tasks (words, nonwords, and digits) and a word list matching task. The central executive (CE) was assessed with 3 tasks (listening, counting, and backward digit recall). Participants were also given a receptive vocabulary task, a reading fluency task, and written stories accompanied by comprehension questions. Canonical correlation analyses showed that the comprehension variables were related to the CE rather than the phonological loop measures. CE functions were more strongly associated with elaborative inference generation (involving significant offline processing) and comprehension control (involving metacognitive monitoring). Smaller yet significant associations were observed between the CE and the necessary inference and literal comprehension measures, whereas a moderate relationship was found in the case of the simile comprehension variable. Among the CE variables, listening recall demonstrated the highest loading on the canonical function, followed by moderate yet significant counting and backward digit recall loadings. Vocabulary was found to fully mediate several associations between working memory and comprehension measures; however, the relationship between listening recall and elaborative inferences was partly mediated. Reading fluency and, on several occasions, Greek vocabulary knowledge did not mediate the relationships between CE measures and comprehension skills assessed. This study demonstrates the usefulness of CE measures for identifying young children's possible difficulties in carrying out specific reading comprehension processes.     

Differential contributions of dorsal vs. ventral hippocampus to auditory trace fear conditioning

The effect of excitotoxic lesions of dorsal vs. ventral hippocampus on the acquisition and expression of auditory trace fear conditioning was examined in two studies. In Experiment 1, animals received excitotoxic lesions of either the dorsal or ventral hippocampus or sham surgeries one week prior to conditioning, and were tested 24 h later. In Experiment 2, animals received excitotoxic lesions of either the dorsal or ventral hippocampus or sham surgeries 24 h after training, and were tested one week after surgery. Both pre- and post-training lesions of ventral hippocampus impaired the acquisition and expression, respectively, of auditory trace fear conditioning. Pre-training lesions of dorsal hippocampus had no effect on the acquisition of trace fear conditioning, while post-training lesions of dorsal hippocampus dramatically impaired expression during subsequent testing. Although in some cases animals with lesions of ventral hippocampus exhibited locomotor hyperactivity, it is unlikely that the pattern of observed deficits can be attributed to this effect. Collectively these data suggest that the dorsal and ventral hippocampus may contribute differentially to the mnemonic processes underlying fear trace conditioning.     

Early German approaches to experimental reading research: The contributions of Wilhelm Wundt and Ernst Meumann

Summary Wundt looked at the reading process from a predominantly theoretical perspective. He opposed the total shape theory formulated by Erdmann and Dodge and insisted on the occurrence of attention shifts during word recognition. As an alternative to the total shape theory, he formulated a two-stage theory of word recognition. An initial, apperceptive phase of reading is concerned with the active analysis of visually salient local details, and a second, assimilative phase fills in the unanalyzed parts of words on the basis of a passive evocation of earlier experiences with graphemic input. Meumann looked at the reading process from the point of view of an educational psychologist. His review of experimental reading research presents most of the basic issues which are still controversial today. In his recommendations for the teaching of reading, he emphasized the importance of analyzing words into their constituent sounds and of articulatory awareness as a precondition for the firm establishment of connections between graphemes and speech sounds. The review discusses some of the reasons why the experimentally based approach to the psychology of reading failed to evoke the interest of German educators after World War I.     

Linguistic and perceptual-motor contributions to the kinematic properties of the braille reading finger

Recordings of the dominant finger during the reading of braille sentences by experienced readers reveal that the velocity of the finger changes frequently during the traverse of a line of text. These changes, not previously reported, involve a multitude of accelerations and decelerations, as well as reversals of direction. We investigated the origin of these velocity intermittencies (as well as movement reversals) by asking readers to twice read out-loud or silently sentences comprising high- or low-frequency words which combined to make grammatical sentences that were either meaningful or nonmeaningful. In a control condition we asked braille readers to smoothly scan lines of braille comprised of meaningless cell combinations. Word frequency and re-reading each contribute to the kinematics of finger movements, but neither sentence meaning nor the mode of reading do so. The velocity intermittencies were so pervasive that they are not easily attributable either to linguistic processing, text familiarity, mode of reading, or to sensory-motor interactions with the textured patterns of braille, but seem integral to all braille finger movements except reversals. While language-related processing can affect the finger movements, the effects are superimposed on a highly intermittent velocity profile whose origin appears to lie in the motor control of slow movements.     

An interactive Hebbian account of lexically guided tuning of speech perception

We describe an account of lexically guided tuning of speech perception based on interactive processing and Hebbian learning. Interactive feedback provides lexical information to prelexical levels, and Hebbian learning uses that information to retune the mapping from auditory input to prelexical representations of speech. Simulations of an extension of the TRACE model of speech perception are presented that demonstrate the efficacy of this mechanism. Further simulations show that acoustic similarity can account for the patterns of speaker generalization. This account addresses the role of lexical information in guiding both perception and learning with a single set of principles of information propagation.     

The role of the ventral and dorsal pathways in reading Chinese characters and English words

Previous literature in alphabetic languages suggests that the occipital-temporal region (the ventral pathway) is specialized for automatic parallel word recognition, whereas the parietal region (the dorsal pathway) is specialized for serial letter-by-letter reading ( [Cohen et al., 2008] and [Ho et al., 2002] ). However, few studies have directly examined the role of the ventral and dorsal pathways in Chinese reading compared to English reading. To investigate this issue, we adopted the degraded word processing paradigm used by Cohen et al. (2008) and compared brain regions involved in the processing of degraded Chinese characters and English words during lexical decision, using functional magnetic resonance imaging (fMRI). The degraded characters/words were created by inserting blank spaces between radicals of Chinese characters or syllables of English polysyllabic words. Generally, the current study replicated the effects of Cohen et al. (2008), showing that in Chinese – like in alphabetic languages – character spacing modulates both ventral (bilateral cuneus, left middle occipital gyrus) and dorsal (left superior parietal lobule and middle frontal gyrus) pathways. In addition, the current study showed greater activation in bilateral cuneus and right lingual gyrus for Chinese versus English when comparing spaced to normal stimuli, suggesting that Chinese character recognition relies more on ventral visual-spatial processing than English word recognition. Interestingly, bilateral cuneus showed monotonic patterns in response to increasing spacing, while the rest of the regions of interest showed non-monotonic patterns, indicating different profiles for these regions in visual-spatial processing.     

Interactions of reading and semantics along the ventral visual processing stream

Converging evidence supports a distributed-plus-hub view of semantic processing, in which there are distributed modular semantic sub-systems (e.g., for shape, colour, and action) connected to an amodal semantic hub. Furthermore, object semantic processing of colour and shape, and lexical reading and identification, are processed mainly along the ventral stream, while action semantic processing occurs mainly along the dorsal stream. In Experiment 1, participants read a prime word that required imagining either the object or action referent, and then named a lexical word target. In Experiments 2 and 3, participants performed a lexical decision task (LDT) with the same targets as in Experiment 1, in the presence of foils that were legal nonwords (NW; Experiment 2) or pseudohomophones (PH; Experiment 3). Semantic priming was similar in effect size regardless of prime type for naming, but was greater for object primes than action primes for the LDT with PH foils, suggesting a shared-stream advantage when the task demands focus on orthographic lexical processing. These experiments extend the distributed-plus-hub model, and provide a novel paradigm for further research.     

iSTART: interactive strategy training for active reading and thinking.

Interactive Strategy Training for Active Reading and Thinking (iSTART) is a Web-based application that provides young adolescent to college-age students with high-level reading strategy training to improve comprehension of science texts. iSTART is modeled after an effective, human-delivered intervention called self-explanation reading training (SERT), which trains readers to use active reading strategies to self-explain difficult texts more effectively. To make the training more widely available, the Web-based trainer has been developed. Transforming the training from a human-delivered application to a computer-based one has resulted in a highly interactive trainer that adapts its methods to the performance of the students. The iSTART trainer introduces the strategies in a simulated classroom setting with interaction between three animated characters-an instructor character and two student characters-and the human trainee. Thereafter, the trainee identifies the strategies in the explanations of a student character who is guided by an instructor character. Finally, the trainee practices self-explanation under the guidance of an instructor character. We describe this system and discuss how appropriate feedback is generated.     

The relation between oral reading miscue patterns and comprehension: A test of the relative explanatory power of psycholinguistic and interactive views of reading

The use of oral reading to assess silent reading ability has gained wide acceptance despite the lack of definitive evidence that the two processes are similar. Moreover, there are a number of theoretical positions that run counter to assumptions underlying oral reading error analysis as a measure of silent reading competency. This study examined the relation between multiple oral reading miscue measures and postreading comprehension performance. Correlations between the oral reading and comprehension measures indicated a negative relation between oral reading and recall following the reading of familiar passages and a positive relation between oral reading and an inferential comprehension measure following the reading of unfamiliar passages. In addition, when the subjects read disrupted passages, their attempts at correcting incongruous errors and their self-report interviews indicated that their oral reading was not related to their performance on comprehension product measures. The results, which are discrepant with previous research relating oral reading to comprehension, are discussed in terms of a comparison between psycholinguistic and interactive models of reading comprehension.     

Basic processes in reading: A critical review of pseudohomophone effects in reading aloud and a new computational account

There are pervasive lexical influences on the time that it takes to read aloud novel letter strings that sound like real words (e.g.,brane frombrain). However, the literature presents a complicated picture, given that the time taken to read aloud such items is sometimes shorter and sometimes longer than a control string (e.g.,frane) and that the time to read aloud is sometimes affected by the frequency of the base word and other times is not. In the present review, we first organize these data to show that there is considerably more consistency than has previously been acknowledged. We then consider six different accounts that have been proposed to explain various aspects of these data. Four of them immediately fail in one way or another. The remaining two accounts may be able to explain these findings, but they either make counterintuitive assumptions or invoke a novel mechanism solely to explain these findings. A new account is advanced that is able to explain all of the effects reviewed here and has none of the problems associated with the other accounts. According to this account, different types of lexical knowledge are used when pseudohomophones and nonword controls are read aloud in mixed and pure lists. This account is then implemented in Coltheart, Rastle, Perry, Langdon, and Ziegler’s (2001) dual route cascaded model in order to provide an existence proof that it accommodates all of the effects, while retaining the ability to simulate three standard effects seen in nonword reading aloud.     

Mislocated fixations can account for parafoveal-on-foveal effects in eye movements during reading

Contrasting predictions of serial and parallel views on the processing of foveal and parafoveal information during reading were tested. A high-frequency adjective (young) was followed by either a high-frequency word(n) (child) or a low-frequency word(n) (tenor), which in turn was followed by either a correct (performing) or an orthographic illegal word(n + 1) (pxvforming) as a parafoveal preview. A limited parafoveal-on-foveal effect was observed: There were inflated fixation times on word(n) when the preview of word(n + 1) was orthographically illegal. However, this parafoveal-on-foveal effect was (a) independent of the frequency of word(n), (b) restricted to those instances when the eyes were very close to word(n + 1), and (c) associated with relatively long prior saccades. These observations are all compatible with a mislocated fixation account in which parafoveal-on-foveal effects result from saccadic undershoots of word(n + 1) and with a serial model of eye movement control during reading.     

Mislocated fixations can account for parafoveal-on-foveal effects in eye movements during reading

Contrasting predictions of serial and parallel views on the processing of foveal and parafoveal information during reading were tested. A high-frequency adjective (young) was followed by either a high-frequency word_n (child) or a low-frequency word_n (tenor), which in turn was followed by either a correct (performing) or an orthographic illegal word_{n + 1} (pxvforming) as a parafoveal preview. A limited parafoveal-on-foveal effect was observed: There were inflated fixation times on word_n when the preview of word_{n + 1} was orthographically illegal. However, this parafoveal-on-foveal effect was (a) independent of the frequency of word_n, (b) restricted to those instances when the eyes were very close to word_{n + 1}, and (c) associated with relatively long prior saccades. These observations are all compatible with a mislocated fixation account in which parafoveal-on-foveal effects result from saccadic undershoots of word_{n + 1} and with a serial model of eye movement control during reading.     

Understanding print: early reading development and the contributions of home literacy experiences

This study explored the development of children's early understanding of visual and orthographic aspects of print and how this is related to early reading acquisition. A total of 474 children, ages 48 to 83 months, completed standardized measures of phonological awareness and early reading skills. They also completed experimental tasks that tapped their understanding of what constitutes "readable" print. The parents of participants completed a questionnaire regarding their children's home literacy experiences. The data showed systematic development in children's understanding of print conventions and English orthography and spelling. Regression analyses indicated that print knowledge was related to early reading skill, even after accounting for variance due to age and phonological awareness. Furthermore, parents' ratings of the extent of their children's involvement in activities that led to practice in reading and writing most consistently predicted the development of emerging literacy skills, including understanding of the conventions of the English writing system. Little relation between print knowledge and the frequency of storybook reading by adults was observed.     

Effects of visual complexity and sublexical information in the occipitotemporal cortex in the reading of Chinese phonograms: a single-trial analysis with MEG

We employ a linear mixed-effects model to estimate the effects of visual form and the linguistic properties of Chinese characters on M100 and M170 MEG responses from single-trial data of Chinese and English speakers in a Chinese lexical decision task. Cortically constrained minimum-norm estimation is used to compute the activation of M100 and M170 responses in functionally defined regions of interest. Both Chinese and English participants’ M100 responses tend to increase in response to characters with a high numbers of strokes. English participants’ M170 responses show a posterior distribution and only reflect the effect of the visual complexity of characters. On the other hand, the Chinese participants’ left hemisphere M170 is increased when reading characters with high number of strokes, and their right hemisphere M170 is increased when reading characters with small combinability of semantic radicals. Our results suggest that expertise with words and the decomposition of word forms underlies processing in the left and right occipitotemporal regions in the reading of Chinese characters by Chinese speakers.