*3.1. Basic Mechanism: Brain and Function*

The cerebral cortex of the human brain is roughly two cerebral hemispheres in a longitudinal division. When assuming normal right-handedness, the left hemisphere controls the right side of the body, while the right hemisphere controls the left side. In cognitive processing of information, the left hemisphere shows a more sequential fashion, and the right hemisphere appears in a simultaneous manner. Therefore, the left hemisphere is better at dealing with language material, and the right side is good at planning visual space, learning, and adapting to new situations.

The sulcus also divides the brain into parts. The area anterior to the central sulcus is the frontal lobe, and posterior to the central sulcus lies the temporal, parietal, and occipital lobes. The behavioral outputs associated with the frontal lobe include motor programming, abstraction, planning, and self-regulation. The temporal lobes mainly link

to the auditory channel. The parietal and occipital lobes correspond to somatosensory and visual stimuli [3,14]. As Figure 2 shows, in electroencephalogram (EEG) experiments and analysis, researchers often divide the brain into 21 electrode positions, which correspond to different function divisions by the international 10–20 electrode lead system [15]. In the EEG electrode system, odd numbers represent left and even numbers represent right. The prefix AF denotes electrodes of the frontal lobe and FC denotes electrodes between the frontal and central lobes; F, T, C, O, and P denote frontal, temporal, central, occipital, and parietal lobes; and the others such as Fp, Fz, Cz, and Pz are marker sites. For example, T8 stands for the electrode of the temporal lobe on the right side. All these channels are used for recording and describing the application locations of scalp electrodes in an EEG test. To better interpret the results, these channels can be divided into four groups: left cluster (AF3, F7, F3), right cluster (AF4, F8, F4), center cluster (FC5, FC6, T7, T8), and back cluster (P7, P8, O1, O2).

**Figure 2.** Neuropsychological mechanism of behavior. The electrode lead system on the left is adapted from Wang et al. (2017), and the others are drawn by the authors.

#### *3.2. Main Process: From Sensory to Decision*

After perceiving external stimuli and cognitively processing the information, the result of individual behavior usually reveals itself as decision-making in various situations and at different times. That is, human behavior usually goes through three main processes: perception, cognition, and decision-making before acting (Figure 2).

Perceptual behavior includes two main stages: sensation and perception. Sensation refers to the stage that organs receive from external stimuli. Perception indicates information understanding and explanation, including the physiological processing of the brain based on scientific information and psychological processing based on experience [16]. We can classify perception as visual perception, auditory perception, chemical perception (mainly olfactory and taste), and tactile perception (including pain). Based on sensation and perception, researchers have proposed more comprehensive perceptual concepts, such as spatial perception [17] and risk perception [18]. More studies pay attention to the connection between self and environment, behavioral individuals and physical objects, independents, and society [19]. In the preliminary design stage of construction, multiple perceptions are involved, such as visual perception when browsing contract content and

design drawings, as well as auditory perception of noise, olfactory perception of air quality, and tactile perception of building materials during fieldwork. During the operating stage, equipment operators often must remark on multiple areas at the same time (the building site in front, the control panel in hand, other workers, and equipment in the surrounding areas, etc.). It is necessary to mobilize more complex perception capabilities and maintain them for a long time, such as spatial perception and risk perception [20].

Cognitive behavior also has two views: behaviorist and cognitivism. Behaviorist views take the neuropsychological mechanism as a "black-box", while cognitivism regards neuropsychological mechanisms as the progress of information working [21]. Cognitive behavior research and empirical experience provides many ideas, such as attention and interest stimuli, emotion arousal and valence, mental schema and classification, states of consciousness and memory, mindfulness, flow, and others [22,23]. Cognitive behavior also considers the interrelationships between these ideas; for example, the literature has found a strong connection between attention and memory development [24,25]. In construction engineering, researchers also explored the interrelationship between visual attention and memory experimentally and validated this in building inspections [26].

Decision-making behavior is more common in marketing research. Consumer neuroscience is defined as the application of neuroscience theories and tools to better understand human decision-making and related behaviors [4]. It is considered an interdisciplinary academic branch of marketing and neuroeconomics, including decision neuroscience, and is also supposed to be the intersection of neuroscience and consumer psychology. In fact, marketing processes are also unavoidable for construction management when requiring economic benefits. From this perspective, using relevant theories and methods in neuroscience to understand decision-making processes in construction management is also feasible. Behavior science ties into the design, analysis, evaluation, and choice of proposals, and the visual attention and information acquisition when reading a contract. Moreover, this includes the complex cognition of final discrimination [27,28]. For a more precise task, the operator's mobilization of various sensory functions of the body and the feedback of the brain's neural mechanisms would affect each control action [29].

#### *3.3. Core Factors: Functional Ingredients*

Motional behavior is implemented through the interaction of neuronal firing and functional circuits. Simplified brain regions and abstract concepts are often used to organize relevant knowledge, which means using basic functional ingredients to describe neuropsychological progress. Neural circuits of attention, emotion, and memory are ubiquitous in decision-making [30]. Neural control of learning and motion is also produced when a behavior takes place [31,32], which constitutes the main neuropsychological unit of behavior analysis [33].

Attention refers to mental engagement that focuses on specific information. When the information enters consciousness, the mind will learn about the specific items and decides whether to act [34]. Attention is also defined as the individual's choice of previous information from specific stimuli in a social context [35]. As conscious visual evidence, an approximately stable nervous system is behind attention [36]. Similarly, the neuropsychological mechanism behind visual attention is a cognitive-driven information system in construction engineering [26]. Sweany et al. (2016) have analyzed the effects of the format of engineering deliverables on craft performance based on empirical data [37]. They found the 3-dimensional computer aided design (3D CAD) model can improve the accuracy of workers' spatial cognition and the efficiency of completing preset tasks more than 2D. However, because of additional information of architectural textures, colors, and directions increases the cognitive burden of human beings, 3D models or virtual reality (VR) and augmented reality (AR), etc., are not better than traditional 2D drawings in conveying spatial information [38,39].

Learning and memory often occur at the same time because acquiring knowledge from the surrounding environment is a key condition for memory creation. At the end of the 19th century, German experimental psychologist Ebbinghaus used meaningless syllables to evaluate the effect of learning and memory and proposed the famous forgetting curve. Since the 1980s, the memory system has gained more understanding. People had divided it into sensory memory, short-term memory, and long-term memory, and further, divided short-term memory into working memory and reference memory, as well as dividing longterm memory into declarative memory and non-declarative memory (or explicit memory and implicit memory). In the field of construction engineering, limited studies focus on environmental components and spatial cognition application and lack in-depth exploration of memory [40,41].

The feature of emotion is intense sensory arousal associated with specific behavioral responses, which embodies the assessment of specific stimuli related to or irrelevant of individual or group goals [42]. Such assessment is a cognitive process that relies on the environment or proprioception. Additionally, it is taken as an attempt to maintain, establish, disrupt, or terminate connections between the individual and environment that are of great significance [18]. Therefore, Frijda (2009) argued that emotion is a process rather than a state, and that it is a subconscious event triggered by evaluating relevant stimuli in a limited dimension [43]. Moreover, this evaluation determines the strength and quality of behavioral tendencies, physiological responses, sensations, and behaviors. Current construction engineering management research has paid attention to the measurement and evaluation of emotional situations and their impact on work operations; for instance, mental fatigue [7,8] and stress [44]. Therefore, more neuropsychological analysis is still needed.

Motion control involves neural activation in multiple regions of the cerebral cortex and mass signal transmission by ganglions. Specifically, the auxiliary motor area found in the inner side of the brain controls the fingers moving [45]. When a motion needs to be completed under conditions of visual, auditory, or somatosensory feedback, the premotor cortex of the brain will be activated to extract rich representations of sensory information [46].

#### **4. Neuropsychological Methods and Application**

Before the neuropsychological technologies and methods led into behavior research, researchers widely used self-reporting methods in psychology (such as interviews and questionnaires) in behavioral research. However, the retrospective reflection of behavioral subjects is often biased [47]. To seek more reliable and accurate measurements, behavior researchers have been attempting biological psychology and neuropsychological technologies and methods, such as electrodermal response experiments in the 1920s and pupillary dilation experiments in the 1960s [48]. Afterwards, wearable devices, such as eye-tracking and heart rate measures, are becoming more acceptable because of their convenience [49]. Recently, researchers used neuroscience techniques, with electroencephalogram (EEG), functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS) as the main types, to study the emotional and cognitive responses of behaving individuals. The results promote the behavior research based on neuroscience and neuropsychology [30]. There are also researchers that are pointing out that the paradigm of neuropsychology is shifting to digital neuropsychology and will form a high-dimensional neuropsychological assessment through simulation computing [50].

#### *4.1. Tradition: Subjective Evaluation and Self-Report*

Early neuropsychological assessments rely primarily on evaluation and self-report methods. They can often be categorized as qualitatively or quantitatively focused. Qualitative assessments are derived from approaches of behavioral neurology and rely on intuitive insight, which requires considerable knowledge of neurology [2]. Compared to the subjective evaluation of the evaluator, another perspective is the oral retrospective statements, such as in-depth interviews, ladder interviews, and focus interviews or written language statements of open-ended questionnaires based on self-knowledge. Quantitative assessments are attributed to clinical neuropsychology, emphasizing standardized psychometric tests. Quantitative analysis has formed various scales and tests, including the Wechsler Intelligence Scale (WISC), Minnesota Multiphasic Personality Inventory (MMPI), Tactual Performance Test (TPT), Finger-tapping Test (FT), Speech Sounds Perception Test (SSPT), Rhythm Test (RT), Train Making Test (TMT), and sensory perceptual examination, etc.

In the spatial perception and cognitive behavior closely related to architecture and construction, researchers have put forward and applied the cognitive map [51]. In practice, the cognitive map means "maps in the mind" and hypothetical constructions of map metaphors and is the visual expression of space. Researchers have asked people to express spatial form in the mind using painting. Passini (1984) pointed out in more detail that cognitive maps reflect people's cognitive and behavioral abilities in space [52]. This ability is based on three direct manifestations—information processing, decision-making, and task execution—reflecting the solving ability in response to spatial problems. Considering the differences in psychological comfort, spatial anxiety, and behavioral dependence, relevant staff should have higher spatial perception and expression skills [53–55]. Research on escape behavior during fire drills has also shown that people with higher spatial abilities are better able to understand building structures and symbolic representations, which means higher building space design, disaster prevention, and condition controlling capabilities [56,57].

#### *4.2. Current: Precise Exam and Image Technology*

There are three major spectrum techniques for precise examinations and images in neuropsychological diagnosis: physical neurological exam (PNE), computed axial tomography scan (CT), and EEG. PNE needs a standard physical examination (usually lasting more than 20 min) and a detailed medical history, so it is usually performed by medical professionals [58]. CT combines a computer and traditional X-ray machine to take brain pictures from multiple locations through X-ray. Then, they are transmitted to a computer for data conversion and analysis, resulting in a visualization of the density of different brain tissues on a cathode-ray screen. However, despite CT having higher cost-effectiveness, the false-negative errors still have a 50% occurrence, and so it needs to be combined with other measurements.

EEG acquires brain wave data by attaching electrodes to specific regions of the frontal, temporal, parietal, and occipital lobes. It can interpret brain activity based on brain waves, and so it is more closely related to the neural activity in the brain [59]. However, it also should be noted that since 15–20% of the normal population will have abnormal EEGs, the results of EEG analysis may have false-positive errors. An EEG experiment found that noise can affect the information machining process of construction workers [60]. Under the influence of high noise, construction workers will have higher self-depletion and show a behavioral tendency to seek rewards. The result means the workers need a longer response time for behavioral decision-making, increasing the risk of hazardous behavior.

#### *4.3. Future: Wearable Devices and Computer Simulation*

Neuropsychologists and behaviorists in the digital age have increasing access to emerging technologies. Relying on the technological advancement of portable wearable devices, behavioral research is no longer limited to the laboratory environment. Researchers can conduct behavioral experiments in real scenes and the real world, and it has been used in some fields such as tourism, marketing, transportation, etc. [49].

Eye-tracking can explain the neuropsychological mechanism of visual perception behavior by recording the process of eye movement. Existing research usually visualized tracking results through a heat map and trajectory map to illustrate potential neuropsychological responses functionally and effectively. Eye-tracking research has developed from the initial observation of appearance characteristics to accurate measurement records and formed modern technology to analyze eye movement patterns. It has become an important method in the research of spatial cognition, map cognition, map systems, and other fields [61]. In construction engineering and management, wearable devices are also applied in research of mental fatigue, hazard detection [8,62], fairness perception [27,28], and performance behavior [63] of construction contractors in contract signing.

Wearable and wireless EEG device systems can quantitatively and automatically assess the attention level of construction workers by recording and analyzing signals of the brain. EEG signal characteristics, such as frequency, power spectral density, and spatial distribution, can effectively reflect and quantify the perceived risk level of construction workers. Meanwhile, the lower gamma frequency band and left frontal lobe EEG cluster directly and appreciably show the worker's state of alertness [15]. Compared to fMRI and fNIRS, EEG provides higher temporal resolution but lacks spatial resolution [64–66]. The sampling frequency of fNIRS is relatively low (less than 20 Hz), but the spatial resolution is higher, which is crucial for monitoring brain regions associated with mental loading [67,68]. In empirical research, Shi et al. (2020) built a virtual industrial maintenance scenario to present a human–subject experiment, and to examine the impact of information format on the performance of a pipe maintenance task, as well as the implications of cognitive costs in both working memory development (information encoding) and retrieval (information recalling) [44]. The research aimed to establish an evaluation system for predicting engineering performance and then inspire the design of personalized training systems driven by cognition in construction engineering.

Moreover, computational simulation is considered a high-dimensional technique of neuropsychology in the continual development of VR, AR, and mixed reality (MR). The behavioral and social science initiative of the National Institutes of Health (NIH) highlights the developing scientific and technological potentials (such as new sensors), and to enhance the characterization of neurocognitive, behavioral, emotional, and social understanding. Jolly and Chang (2019) considered that neuropsychological assessments that are two-dimensional may previously have had a flatland fallacy [69]. They suggest that this fallacy can be overcome by formalizing psychological theories into computational models, making it capable for predicting cognition and behavior precisely. Simulating the parallel, reciprocal, and iterative interactions between the environment and neural function of complex behavior can enhance the ability of actual operations [50]. Building Information Modeling (BIM) is a beneficial attempt at visualization and predictability in construction engineering, as well as Heritage Building Information Modeling (HBIM) and BIM+. However, such models are still limited to the simulation and calculation of architecture or building substance, while the behavior simulation and more subtle neural mechanisms are still difficult to achieve.

As Table 1 shows, whether it is an objective measurement dominated by technical tools or a subjective judgment dominated by self-report, each method has its advantages and limitations. There is a growing consensus that researchers using neuroscientific methods and devices must have qualitative knowledge or experience of the phenomenon. Then, the researchers can reasonably interpret neuropsychological indicators and the signals they represent. As Plassman et al. (2015) claim, the fullest explanation of consumer and managerial behavior requires a combination of neuroscientific measurements and subjective explanations [4]. When combining the methods, researchers will draw the most productive and profound conclusions, as the advantages of one method outweigh the disadvantages of the other.


**Table 1.** Comparison of neuropsychological methods.

#### **5. Behavior Research in Construction Engineering Management**

*5.1. Behavioral Turns of Method: Neuropsychological Experiment*

In addition to focusing on economic issues such as economic benefits and cost control, engineering issues such as construction technology and schedule control must also be given attention. Construction engineering and management also pays attention to management issues such as organizational systems and contract signing. This shows the research content has gradually shifted from focusing on objects such as equipment, materials, and structures, to focusing on humans; that is, the behavioral response of individuals or organizations to system design and management processes. However, single and traditional methods

inevitably have shortcomings in data acquisition or measurement, and it is difficult to infer the influencing factors of management and decision-making.

Through scientific design and critical control, behavioral analysis and experimental methods can improve the reliability of data and the interpretability of research results. Figure 3 summarizes the general process of behavioral experiments and neuropsychological experiments. Applicable experimental designs in construction engineering and management include single-station passive observation, contrast experiments, and randomized experiments [70]. In practical application, these experiments should ensure the controllability of the environment, the systematisms of the research content, and the predictability of the research conclusions. Few Chinese researchers also prefer to apply the behavioral experiment to construction engineering and management. For example, Li et al. (2012) took computational experiments as a research method to discuss the multistage group incentive problem when considering the fairness perception of individual contractors [71]. To sum up, research methods applied in construction engineering and management have transitioned from framed qualitative research to model-based quantitative research. However, the application of neuropsychological experimental methods is still in infancy [72].

**Figure 3.** Neuropsychological experiment process. Drawn by the authors.

#### *5.2. Bibliometric Analysis: Countries (Regions) and Hot Issues*

5.2.1. Countries (Regions) Cluster and Timing Progress

By choosing bibliographic coupling as the analysis type and countries as the analysis unit, with the minimum number of documents as six, forty countries or regions meet the thresholds. The countries or regions of publications are shown in Figure 4, and the ten countries (regions) with the most publications are shown in Table 2. From the results, researchers from Taiwan, China have begun to pay more attention to the neuropsychological mechanisms of individual behavior in CEM earlier and have published some achievements. Then, American researchers have focused on this field and have published a large number of achievements. After that, researchers from Australia, Canada, England, France, and Spain also began to get involved in neuropsychological research and published some achievements. In these countries (regions), Australia has the most publications. Indian

scholars then paid attention to this research topic and carried out some related research. In the most recent time period, Italian researchers also realized the important role of neuropsychology in revealing behavioral mechanisms and carried out lots of research in the CEM field. At the same time, Chinese scholars attended to this field; these researchers tried to introduce neuropsychological theories and methods into construction engineering management and its behavioral research, and thus a large number of achievements have been published.

**Figure 4.** Countries (regions) and timing progress. The "Taiwan" in this figure refers to "Taiwan, China".

**Table 2.** Distribution and timing progress examples of existing publications.

