potential other, improved alternative resources. A fundamental specialization of the primate FPC was concerned with addressing competing goals by monitoring both current and possible alternative goals and adjusting behaviors. The human FPC (lateral subdivision of BA 10) circuitry enabled the monitoring of diverse competing goals simultaneously, and the ability to transition between them. These cortical advance
ments allowed for the options of responding to environmental challenge by aborting the exploitation of a current food or reward source in favor of exploring new avenues and thereby rendering a survival advantage. The human FPC is also concerned with integrating abstract information, creativity, and social cognitive and emotional processes. The developing frontoparietal brain circuitry endowed primates and humans with a balance of posterior PFC located exploitation related impulses and FPC
centered exploratory drive that delegates a redistribution of resources away from the current task, which is an advantage when competing goals might be more beneficial due to a change in circumstances (Figure 5.2). Unsurprisingly, people with FPC related lesions are often normal by cognitive testing but have significant impairments with regard to dealing with novel or open ended situations and simply with managing day
today challenges [43].
An all important FPC function involves the concepts of metacognition and intro
spection. As decision outcomes may be encoded in prefrontal and parietal cortical brain activity up to ten seconds before entering awareness, the concept of non conscious components of free decisions in the human brain has emerged [44]. Research into the process of prospective judgments has been evaluated in terms of “feelings of knowing,”
and judgment of learning is used to refer to the estimation of how successful a person’s recall is thought to be [45].
In addition to the FPC, white matter microstructure has also been shown to correlate with introspective ability, including the genu of the anterior corpus callosum (CC) with subdivision of the CC fibers connected with the anterior and orbital prefrontal cortex, showing that metacognition is dependent not only on anterior prefrontal gray matter, but also on reciprocal projections [46]. The neural signature of self control also involves a veto function and final predictive check, which involves the anteromedian cortex and anterior insula [47].
Table 5.1 Secondary syndromes
Behavioral Multiple disinhibition syndromes
Field-dependent behavior syndromes Disinhibitory control syndromes
Cognitive Executive dysfunction syndromes
Multitasking impairment Motor sequencing impairments Motor dysphasia syndromes
Motor Abulic spectrum of disorders
Eye movement syndromes Obsessive and compulsive disorders Alien hand syndromes
Disconnection (hodological) syndromes Emergent visual artistic proficiency Emergent musical artistic proficiency Cerebellar cognitive affective syndrome
Frontopolar Cortex 95
Interpersonal Cognition before Intrapersonal Cognitive Control
As cooperation became a central feature of the human way of life, with coordinated joint action and organized cooperative projects, a supra personal system of cognitive control evolved. The cognitive processes for intrapersonal cognitive control are thought to have come second and arose as a development of the selection of a system of metacognition for interpersonally coordinated action. Shea et al. propose a two part model: that of a cog
nitively lean, system 1 metacognition operating “implicitly” for the control of processes within one agent (intrapersonal cognitive control), which is common in many animals;
and a cognitively rich system 2, or metacognition, thought to be unique to humans for controlling processes related to multiple agents, referred to as supra personal cognitive control (Figure 5.3) [48].
Hence metacognition evolution can be viewed as a sequence of mirror neuron sys
tem elaborations, followed by evolution of metacognition for interpersonally coordinated action, then metacognition for intrapersonal cognitive control, and finally emotional intelligence.
A meta analysis of action studies of healthy young adults revealed that episodic mem
ory and retrieval of working memory were associated with lateral activations of the fron
topolar region. In addition, other memory processes associated with FPC activity include retrieval verification, contextual recollection, source memory, and prospective memory.
Studies concerned with mentalizing or paying attention to one’s emotions or the mental
Premotor
Medial frontal
Lateral prefrontal
Frontopolar
Unidirected exploration
Directed exploration
Exploitation
Medial frontopolar cortex
Lateral frontopolar cortex
Goal-directed behaviour
Monitoring a few alternative tasks/
goals for possibly re-engaging one as replacement of the current task/goal pSMA
Posterior prefrontal cortex
Recruiting and implementing cognitive control to optimize the performance of the current goal
Monitoring the current goal for possibly redistributing cognitive control resources to other potential goals
Figure 5.2 The principal frontal cortical subregions and functions.
Reproduced by permission from Springer Nature from Mansouri FA, Koechlin E, Rosa MGP, Buckley MJ.
Managing competing goals: a key role for the frontopolar cortex. Nat Rev Neurosci 2017;18:645–657.
states of other people were associated with medial activations of the frontopolar region.
The FPC is not interconnected with other cortical downstream areas as is the case with the prefrontal cortical areas. Its connections are limited to the supramodal PFC cortical areas, the anterior temporal cortex, and cingulate cortices. Furthermore, a hierarchy of function exists whereby the ventrolateral PFC (BA 12, 45, and 47) function is for the active retrieval of information from long term storage sites, usually for one or several items of information. The dorsolateral PFC (BA 9 and 46) mediates the monitoring and manipu
lation of externally derived information. The third component, the overarching function of the FPC (BA 10), mediates the monitoring and manipulation of internally based infor
mation and processes internal states [15]. The other functions of the FPC include cogni
tive branching and multitasking – or holding information of a pending task, completing subtasks, or secondary goals. In this manner, cognitive branching is seen to enable what is termed multitasking. In addition, an important function is that of relational integration or the activity of several different external or internal processes and self referential evalu
ation, important for generation of new strategies in the context of novel activities [49,50].
The pre SMA is located between the PFC and motor areas, the SMA proper, and the primary motor cortex, and is a key structure engaged during voluntary action, transform
ing thoughts into actions. Transcranial magnetic stimulation studies have intimated that the pre SMA function is in the preparation of entire movement sequences but also in suppressing automatic responses to environmental stimuli. Lesions in the pre SMA cause hyper responsiveness [51] and have been associated with utilization behavior (compul
sive grasping of objects in the immediate environment) and anarchic hand syndrome (contralateral hand reacts automatically to a stimulus). These findings are important in understanding field dependent behavior discussed below.
Metacognitive
representations Metacognitive
representations
Action Action
Sensory input
Communication of system 2 metacognitive representations
System 2
System 1 System 1
System 2
Figure 5.3 Lean and rich meta- cognitive systems.
Source: Shea N, Boldt A, Bang D, Yeung N, Heyes C, Frith CD. Suprapersonal cognitive control and
metacognition. Trends Cogn Sci 2014;18:186–193. https://doi.org/10.1016/j.tics.2014.01.006 Reproduced under the CC BY 4.0 license https://creativecommons.org/licenses/by/4.0/
97 Language, Praxis, and Stone-Knapping
FDB Recognition for Diagnosis and Therapy
Fielddependent behavior (FDB) recognition is important to recognize for diagnostic and therapeutic reasons. The mirror neuron systems refer to an extensive frontoparietal network and a neurobiological substrate for several key higher cognitive function abil
ities, including theory of mind, learning by observation, language, and praxis. During primate evolution, the mirror neuron system circuitry became progressively more elabo
rate and complex; a seven stage extended mirror neuron system hypothesis was proposed by Arbib. He suggested that stages 1–3 took place within primate evolution of grasping and simple imitation. From our last common ancestor (LCA) onwards to modern humans, presumably stages 4–7 evolved. The stages are:
1. grasping;
2. mirror system for grasping;
3. simple imitation (shared with chimpanzees but not macaques);
4. complex imitation (beyond chimpanzees);
5. protosign (key innovation; open repertoire);
6. protospeech (key innovation; neocortical vocal control via collateralization);
7. modern language [52].
A variety of frontal lobe lesions frequently cause FDB syndromes that have been attributed to a disruption or an uncoupling of the brain’s mirror neuron system circuitry.
The concept of theory of mind, our intentionalities, social cognition, and language are all integral to the MNS [53]. The diagnosis of FDB is especially important, because one of the consequences may be loss of personal autonomy of someone who appears on the surface quite normal, with relatively intact cognition and who may be actively employed. Lesion studies have revealed that the superior part of the SMA (BA 6 of the frontal lobes) is asso
ciated with what has been termed elementary forms of FDB. Examples include imitation behavior, very similar to echopraxia, as well as utilization behavior. The inferior parts of the frontal lobes, in particular the right orbitofrontal area, are involved when more com
plex FDB syndromes are recognized. Examples include environmental dependency syn
drome [54–56]. There may be a temporal component as well, with imitation behavior and utilization behavior predominating in the early period post injury, such as acute stroke, whereas environmental dependency syndrome tends to develop later in the course of the brain lesion [57–59]. Aside from the diagnostic importance, there are therapeutic impli
cations integral to the mirror neuron system that may be advantageously exploited. For example, with severe motor deficits post stroke, rehabilitation “action observation” tech
niques engage similar circuits to those that are actually involved with performing such an action. To date, differing variations of mirror visual feedback therapy have been shown to be effective in phantom limb pain, stroke, and some neuropsychiatric syndromes [60,61].
There is also evidence that gestural therapy in improving expressive aphasia is based on the rehabilitative aspects [62].