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Varieties of learning and developmental theories of memory
Published in Romain Meeusen, Sabine Schaefer, Phillip Tomporowski, Richard Bailey, Physical Activity and Educational Achievement, 2017
Phillip Tomporowski, Daniel M. Pendleton, Bryan A. McCullick
Central to perceptual learning is the capacity to capture and recognize events as they occur. At a fundamental level, humans learn about the world they live in based on the experiences they derived from the stimulation of the sensory systems. Consider, for instance, how one can pick out the face of a friend in a crowded room. As the features of every person’s face are unique, they reflect a specific array of light waves that enter the eyes and stimulate photoreceptors on the retina that, in turn, send neural transmissions through the lateral geniculate of the thalamus and on to the striate cortex and the primary visual cortex. There the attributes of the incoming information flow are analysed in terms of form, colour and movement. Information then separates into two streams: the ventral stream flows towards the inferior temporal lobe and is used to recognize the visual experience; the dorsal stream flows toward the posterior parietal cortex and provides information concerning the location of what is seen. Together, the two streams provide the basis for our ability to recognize objects and their locations.
Rehabilitation and management of visual dysfunction following traumatic brain injury
Published in Mark J. Ashley, David A. Hovda, Traumatic Brain Injury, 2017
Magno cells are, in general, sensitive to large contours, lower contrast, and faster temporal frequencies and are retinotopically distributed more peripherally than parvo cells (reviewed by Bassi and Lemkuhle93). Some magno cells are color-sensitive, but at least half are insensitive to color.94 Approximately 20% of magno cells originating in the retinas are sent to subcortical systems for maintenance of diurnal rhythms, pupillary control, and survival-level orienting and balance. The rest of the magno system is preserved, in a relatively segregated manner, through the primary visual cortex and then as the dorsal stream to the MT area for motion processing (including optic flow, which keeps us oriented when moving through space) and from there to posterior parietal cortex for cortical processing of object localization and visual attention. When damaged, the posterior parietal cortex and the pathways to the frontal cortex arising from the parietal cortex are major substrates for visual–spatial neglect. From the parietal cortex, the dorsal stream trifurcates into a parieto–prefrontal pathway for spatial working memory, a parieto–premotor path for visually guided action, and a parieto–medial temporal pathway for spatial navigation.
The Central Nervous System Organization of Behavior
Published in Rolland S. Parker, Concussive Brain Trauma, 2016
Primary sensory cortex: Each of the sensory cortices have a unimodal sensory association area. To illustrate, we will consider the distribution of the optic nerve tract. The retinal axons proceed to the optic chiasma, where some fibers decussate to the opposite side. The major visual pathway for conscious vision is to the dorsal lateral geniculate nucleus of the thalamus, which projects to the striate cortex of the occipital lobe. Spatial information is related from the striate cortex to the posterior parietal cortex. Form and color information is relayed to the inferotemporal cortex, which is involved in complex functioning, including visual recognition of objects and individuals. Visual projections to the midbrain roof (superior colliculus) are involved with spatial projections of the visual world. Similar associated maps involving auditory and somatosensory space are projected into the deeper layers. Superior colliculus visual input is related to the pulvinar (dorsal thalamus) and then to the extrastriate visual cortical areas bordering the primary visual cortex of the occipital lobe (Butler, 2002) (see Figure 3.1, 3.2, and Figure 3.3).
Spatial neglect treatment: The brain’s spatial-motor Aiming systems
Published in Neuropsychological Rehabilitation, 2022
A. M. Barrett, Kelly M. Goedert, Alexandre R. Carter, Amit Chaudhari
Finally, a true understanding of directional motor biases will require that we are able to consider several neurophysiological fundamental sources of asymmetry. Posterior parietal cortex is (a) involved in motor planning and (b) may support improved movement after rehabilitation in patients with spatial neglect (Mattingley et al., 1998). We also need to measure electrophysiologic, hemodynamic, and cellular activation parameters to test, for example, whether loss of competitive equilibrium between hemispheres (Kinsbourne, 1977), altered gradients of information flow in local circuits (Nakayama et al., 2016), changes in preferred directional tuning at the level of individual neurons, or the disruption of cholinergic, adrenergic and dopaminergic neurotransmission (Luvizutto et al., 2015) may be more likely to account for symptoms. These method may be fruitful to co-integrate with lesion-symptom studies (Karnath et al., 2018), once large groups of well-characterized spatial neglect patients with Aiming spatial neglect are available. Thus, researchers studying spatial neglect rehabilitation should consider (1) dividing patients by presence or absence of frontal/striatal injury, or frontal brain disconnection (2) examining pre/post neurophysiologic parameters such as motor or sensory evoked potentials, brain activation, and brain vascular dynamics (Boukrina et al., 2019).
tDCS effects on task-related activation and working memory performance in traumatic brain injury: A within group randomized controlled trial
Published in Neuropsychological Rehabilitation, 2021
Jacqueline A. Rushby, Frances M. De Blasio, Jodie A. Logan, Travis Wearne, Emma Kornfeld, Emily Jane Wilson, Colleen Loo, Donel Martin, Skye McDonald
Finally, an important limitation has been the placement of the anode in TBI participants. This is commonly placed over the (typically left) dorsolateral prefrontal cortex (Kang et al., 2012; Lesniak et al., 2013; Sacco et al., 2016; Ulam et al., 2015) to improve working memory. However, the frontal lobes are extremely vulnerable to TBI. There is often significant atrophy and increased fluid that alters the conductive path of tDCS in idiosyncratic patterns that reflect individual neuropathology (Wagner et al., 2007). The posterior parietal cortex is also part of the neural network thought to mediate working memory, being activated during working memory tasks (Buchsbaum & D'Esposito, 2008; Olson & Berryhill, 2009; Wager & Smith, 2003). tDCS to the parietal cortex stimulates overlapping frontoparietal neural networks to frontal stimulation and yields equivalent enhancement of working memory (Jones, Stephens, et al., 2015). tDCS to right and left parietal regions has been demonstrated to improve visual working memory (Heimrath et al., 2012; Heinen et al., 2016; Jones, Stephens, et al., 2015; Jones & Berryhill, 2012; Tseng et al., 2012) and verbal learning (Jones, Gözenman, & Berryhill, 2014) respectively in healthy adults. The parietal lobes are less likely to be impacted by TBI (Bigler, 2007) and, therefore, the parietal region was chosen for the current study, with the anode on the left parietal lobe and the cathode placed on the homologous site on the contralateral hemisphere.
Cathodal tDCS of the Left Posterior Parietal Cortex Increases Proprioceptive Drift
Published in Journal of Motor Behavior, 2019
João Roberto Ventura de Oliveira, Marco Aurélio Romano-Silva, Herbert Ugrinowitsch, Tércio Apolinário-Souza, Lidiane Aparecida Fernandes, Juliana Otoni Parma, Guilherme Menezes Lage
Multimodal integration has well-known associations with several cortical areas (Roland, 1993). Among these areas, the posterior parietal cortex (PPC) stands out for its importance in the formation of sensory representations that are involved in both movement planning and error corrections (Andersen, Snyder, Bradley, & Xing, 1997; Culham et al., 2003; Desmurget et al., 1999; Lage et al., 2015; Mutha, Stapp, Sainburg, & Haaland, 2014; Ruschel et al., 2014). Transcranial magnetic stimulation (TMS) applied to the left PPC alters the quality of online corrections (Desmurget et al., 1999) and adjustments of motor commands necessary for adapting to new arm trajectories (Della-Maggiore, Malfait, Ostry, & Paus, 2004). The PPC is usually associated with the formation of proprioceptive drift, but interestingly, to our knowledge, there is no study investigating this association in aiming movements. Transcranial direct current stimulation (tDCS) applied to the PPC interferes in cognitive representations involving spatial memory (England, Fyock, Gillis, & Hampstead, 2015), visual short-term memory (Tseng et al., 2012), and working memory (Berryhill, Wencil, Coslett, & Olson, 2010). Thus, the use of cathodal tDCS on the left PPC may, among other effects, inhibit sensory representations of movement, increasing the magnitude and the rate of the proprioceptive drift in aiming movements without vision.